a. Is Aunionempty setequalsA true for all sets A and B? Select the correct choice below and, if necessary, fill in the answer box to complete your choice. A. Yes, it is true for all sets A and B. B. No, it is not true for all sets A and B. As a counterexample, let Aequals{a,b,c}. In this case, Aunionempty setequalsStartSet nothing EndSet . This is not the same as A, so Aunionempty setnot equalsA. (Use a comma to separate answers as needed.) C. No, it is not true for all sets A and B. As a counterexample, let Aequalsempty set. In this case, Aunionempty setequalsStartSet nothing EndSet . This is not the same as A, so Aunionempty setnot equalsA. (Use a comma to separate answers as needed.) D. No, it is not true for all sets A and B. As a counterexample, let Aequals{a,b,c}. In this case, Aunionempty setequalsempty set. This is not the same as A, so Aunionempty setnot equalsA