What is a possible reason?

A NewsletterSubscription custom object exists that has a key attribute named email of type String and the following script code.

However, the NewsletterSubscription custom object is not persisted.

What is a possible reason?
A . The code shown need to be wrapped in a transaction.
B. The code shown needs to be wrapped in a try/catch block.
C. The code shown is the wrong syntax. The correct syntax is:

Answer: A