Final answer:
The two tags that don't hold any semantic value by themselves are A) and C). A and C are mutually exclusive.
Step-by-step explanation:
The two tags that don't hold any semantic value by themselves are A) and C). A and C are mutually exclusive, which means they cannot occur together in an event. If there is no information given about whether A and B are mutually exclusive, it is safer to assume they are not unless proven otherwise. For example, if A represents the event of rolling an odd number on a fair six-sided die, and C represents the event of rolling an even number, then A and C cannot happen together.