The best way to calculate an overdue date that is two months after a task due date is to use a formula field with the ADDMONTHS() function. This function adds a specified number of months to a date value, and returns a new date value. See [this article] for more information on formula fields.

Schema Builder provides a graphical representation of all standard and custom objects and their field and relationship structure. It's the best tool for visualizing how data objects are interconnected.
Why D (Schema Builder) is correct:Exact Extract:"Schema Builder provides a dynamic environment for viewing and modifying all the objects and relationships in your organization. You can add new custom objects, fields, and relationships directly in the schema." - Salesforce Help | Schema Builder Overview Why not A (Fields & Relationships):That section displays fields for a single object only, not overall relationships.
Why not B (Object Manager):The Object Manager allows object configuration but doesn't visually display relationships.
Why not C (Lightning App Builder):That tool is for UI layout, not data model visualization.
Reference:
Salesforce Help | Schema Builder Overview
Salesforce Platform App Builder Exam Guide | Data Modeling and Management

The recommended solution to grant the customer service agent access to the field is creating a permission set that allows read-only access to the field via Field Level Security and assigning it to the agent. A permission set is a collection of settings and permissions that give users access to various tools and functions. Field Level Security (FLS) is a setting that controls the access level of fields for different profiles or permission sets. The app builder can create a permission set that grants read-only access to the custom field on the account object via FLS and assign it to the agent. Option B is incorrect because creating a new profile to allow for read-only access to the field via FLS and assigning it to the agent is not recommended, as profiles are used to define the baseline permissions and settings for a group of users, and creating multiple profiles for individual users can be hard to maintain. Option C is incorrect because updating the Customer Service Profile already assigned to the agent to allow for read-only access to the field via FLS is not recommended, as this will affect all users who have the same profile, which may violate the security policy. Option D is incorrect because updating the custom field's FLS in setup to allow the agent read-only access to the field is not possible, as FLS can only be set at the profile or permission set level, not at the user level.

The full sandbox should be refreshed after each major release to production. This way, the full sandbox will have the most updated data and metadata from the production org, and can be used for final load and regression testing before the next release. Option A is incorrect because refreshing the full sandbox after user acceptance testing is complete is not necessary, as user acceptance testing can be done in the partial data sandbox or the production org. Option B is incorrect because refreshing the full sandbox after each push from the partial data sandbox is not necessary, as the full sandbox can receive configuration and code changes from the partial data sandbox without refreshing. Option D is incorrect because refreshing the full sandbox after a new user is added to production is not necessary, as adding a new user does not affect the data and metadata in the full sandbox.

Standard buttons can be overridden with a Visualforce page to provide custom functionality or user interface. For example, you can override the New button on an object to display a custom Visualforce page instead of the standard page layout3. Standard buttons that are not available for overrides can still be hidden on page layouts to prevent users from accessing them. For example, you can hide the Delete button on an object to prevent users from deleting records