What happens when you change the characteristic status to locked?

You assigned a released characteristic to a class.

What happens when you change the characteristic status to locked? Note: There are 2 correct Answers to this question.
A . This has no effect on the assigned classes or objects.
B. You can no longer assign this characteristic to other classes.
C. The characteristic is invisible in classes and objects.
D. You cannot change the status as the characteristic is assigned.

Answer: A,B