Question

Which one of the following statements accurately reflects a rule for the use of abbreviations?

Answer 1

The correct answer for your question is "C"

Answer 2

I would say that the correct answer is D. The abbreviation "B.C." should be associated with a number, such as 44 B.C

In the case of A, it is not an abbreviation but a symbol, a representation of the current coin and it is not generally used.
B: You can use them interchangeably, you should choose one or the other.
C: the statement is false because you can use it alone. For example: "She got her Ph.D. in London "