What is the optimal way to implement these requirements?

An org has a requirement that an Account must always have one and only one Contact listed as Primary. So selecting one Contact will de-select any others. The client wants a checkbox on the Contact called ‘Is Primary’ to control this feature. The client also wants to ensure that the last name of every Contact is stored entirely in uppercase characters.

What is the optimal way to implement these requirements?
A . Write an after update trigger on Contact for the Is Primary logic and a separate before update trigger on Contact for the last name logic.
B . Write a Validation Rule on the Contact for the Is Primary logic and a before update trigger on Contact for the last name logic.
C . Write an after update trigger on Account for the Is Primary logic and a before update trigger on Contact for the last name logic.
D . Write a single trigger on Contact for both after update and before update and callout to helper classes to handle each set of logic.

View Answer

Answer: D