Explanation
Opportunity contact roles allow you to track ROI for contacts that are key stakeholders for opportunities. You need to customize the contact role field and add the related list to the opportunity page layout.
References: https://help.salesforce.com/s/articleView?id=sf.opportunity_contact_roles.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.customize_opportunity_contact_role.htm&type=5

Explanation
Conditional visibility is a feature that allows administrators to show or hide screen components in a flow based on certain conditions or criteria. For example, conditional visibility can show only one question on a screen depending on the value of another field or variable. Conditional visibility consists of one or more rules that define when to show or hide a component based on an expression that evaluates to true or false. In this case, the administrator can use conditional visibility to hide the unnecessary question on the screen flow based on the scenario. References:
https://help.salesforce.com/s/articleView?id=sf.flow_ref_elements_screencmp.htm&type=5

Explanation
To create a contact and an opportunity from a lead that is associated with a campaign, and keep the campaign member history, the administrator should convert the lead from the campaign member detail page. This will automatically create a contact, an account, and an opportunity that are linked to the campaign. Deleting, cloning, or adding a contact will not preserve the campaign member history. References:
https://help.salesforce.com/s/articleView?id=sf.campaigns_leads.htm&type=5

Explanation
A formula field is a type of field that calculates a value based on an expression or formula that references other fields or constants. For example, a formula field can display today's date by using the TODAY() function. In this case, the administrator can create a formula field on the account object that updates the audited date field with today's date when the status of the account is changed to 'Audited'. References:
https://help.salesforce.com/s/articleView?id=sf.fields_about_formulas.htm&type=5

Explanation
To enable users to add repeating tasks in Salesforce, the administrator needs to do two things: first, enable the creation of recurring tasks in activity settings under setup; second, add the create recurring series of tasks field on the page layouts for tasks. This will allow users to create a series of tasks that repeat based on a specified frequency and end date. References:
https://help.salesforce.com/s/articleView?id=sf.tasks_repeating.htm&type=5