Which Apex class contains methods to return the amount of resources that have been used for a particular governor, such as the number of DML statements?

Universal Containers decides to use exclusively declarative development to build out a new Salesforce application. Which three options should be used to build out the database layer for the application? Choose 3 answers

Uniersal Containers (UC) is developing a process for their sales teams that requires all sales reps to go through a set of scripted steps with each new customer they create.
In the first steps of collecting information, UC's ERP system must be checked via as a REST endpoint to see if the customerexists. If the customer exists, the data must be presented to the sales rep in Salesforce.
Which two should a developer implement to satisfy the requirements?
Choose2 answer

As part of a data cleanup strategy, AW Computing wants to proactively delete associated opportunity records when the related Account is deleted.
Which automation tool should be used to meet this business requirement?

How should a developer write unit tests for a private method in an Apex class?