Answer is B & C.

Answer is B & C.

Here we process by elimination. I firstly remove the N°D. that option is non-sens. After this i remove the N°C. why do we need to review the profile just for a simple validation. Why do we need to back the system security because of a field security? So the answer is N°A & N°B

The answer is B

The answer is B. Add the fields to the page layout. and C. Update the user's profile to read/write access to both fields. It cannot be D. Add the validation rule to the user's profile., because you cannot add a validation rule to the User's Profile on the Administrator side. Only Developers can made exemptions.

Answer A and D.

I think B is another answer to this question which is missing