<span>The question says,'before you use one of the encyclopedias, check .......... its copyright date'. The correct option is A. This is because, the statement is referring to only one of the encyclopedias, and the correct possessive noun for an inanimate object like encyclopedia is it's. 'Their' will only be correct if the statement is referring to all the encyclopedias.</span>
This question is for you not for other people. You're the one with memories, this is personal information about you. No one online can help you answer that. This is one from you.
Answer:
third line is suitable for main theme