Explanation:

Determine environmental aspects
Determine environmental impacts
Establish criteria to determine the significance of impacts
Determine which impacts are significant
Determine which aspects are significant
Plan actions to be taken
Determine how to evaluate the effectiveness of the actions taken
According to ISO 14001:2015 clause 6.1.2 (Environmental Aspects), an organization must determine the environmental aspects of its activities, products, and services that it can control and influence, and their associated environmental impacts.
Once identified, the organization shall:
Determine the aspects that can have significant impact on the environment using established criteria for evaluating significance. (Reference: ISO 14001:2015, clause 6.1.2) Then, as per clause 6.1.4 (Planning action), the organization needs to:
Plan actions to address significant environmental aspects, legal requirements, and risks/opportunities.
Determine how to evaluate the effectiveness of these actions to ensure continual improvement.
This logical sequence ensures a structured and risk-based approach to identifying and managing environmental impacts.
Reference: ISO 14001:2015 - Clause 6.1.2 and 6.1.4

The correct six questions are A, B, D, F, H and I .
Opening a third shift is a significant operational change, even if the products, materials and processes remain the same. The scale, timing and conditions of operation have changed. This can affect energy use, waste generation, noise impacts, emergency arrangements, operational controls, interested parties and the internal audit programme.
A). Revised the internal audit programme - Correct
The internal audit programme should consider changes affecting the organisation. A new night shift may need to be included in the audit programme because environmental controls may operate differently at night. ISO
/TC 207's reviewed interpretations confirm that the EMS audit programme considers environmental importance, organisational changes and previous audit results.
B). Reviewed the environmental objectives - Correct
Environmental objectives should remain relevant to significant aspects and environmental performance. If production has increased, objectives related to waste, energy, liquid waste or noise may need to be reviewed or updated.
D). Evaluated the extra amount of waste that will be generated - Correct The Production Manager's statement is incomplete. The same process can still create greater environmental impact if it operates for more hours. More production may mean more solid waste, liquid waste and energy consumption.
F). Reviewed the needs and expectations of interested parties - Correct A night shift may affect interested parties differently, especially because loud noise is a significant environmental aspect. Neighbours, regulators, landlords, customers or local authorities may have expectations or requirements linked to night-time operations.
H). Reviewed the emergency response plans - Correct
Emergency arrangements may need revision because the site now operates during the night. Staffing levels, trained emergency responders, spill response, fire response, external communication and access to emergency services may differ during the 10 pm to 6 am shift. ISO/TC 207 interpretations also confirm that relevant information and training on emergency preparedness and response apply to persons working under the organisation's control where appropriate.
I). Reviewed the documented operational procedures - Correct
Operational procedures and controls should be reviewed to confirm that environmental controls are effective on all three shifts. ISO/TC 207 interpretations confirm that ISO 14001 clause 8.1 remains focused on planning and controlling operations associated with significant environmental aspects, compliance obligations, risks and opportunities, and environmental objectives.
Why the other options are not selected:
C may be useful, but it is not one of the strongest ISO 14001 change-impact questions in this scenario.
E is not correct because ISO 14001 does not specifically require a formal documented plan every time the EMS changes.
G is too broad as written; affected responsibilities may need review, but reviewing "all roles" is not the best key question compared with the six selected.

Accredited certification under ISO 14001 refers to certification that has been issued by a certification body that is itself accredited by a national accreditation body. This provides formal recognition that the certification body is competent to perform audits and issue certifications in accordance with ISO/IEC 17021 standards.
According to guidance in ISO 14001 Lead Auditor training materials and ISO/IEC 17021, one of the key benefits of accredited certification is:
"Recognition of the credibility, impartiality, and technical competence of the certification process and the certification body issuing the certificate." This recognition:
Increases stakeholder confidence (e.g., regulators, clients, the public), Supports market access and tender qualifications, Confirms that audits are performed in accordance with international best practices.
Option D correctly reflects the most strategic and system-level benefit of accredited certification.
The other options (A, B, and C) may result indirectly or are not directly linked to the purpose of accreditation.
Reference:
ISO/IEC 17021:2015 - Requirements for bodies providing audit and certification of management systems ISO 14001 Lead Auditor Course Guide - Module on Certification and Accreditation ISO 14001:2015 - Clause 3.1.1 & 3.1.2 (definition of EMS and system credibility)