The most likely answer is A - archaeologist. However, it's possible that C is correct as well.
If we're talking about a location of temple, then this required in-depth research of first hand, second hand, and third hand sources about the whereabouts of the locaton of a certain structure.
A historian would dedicate a lot of his time to read and research ancient scriptures about certain locations which would then give us an idea where we can expect a certain structure.
However, it's also possible that an archaeologist would do that. What is more importantly, archeologists would also do the required field work to go and dig up the remains of a temple and therefore actually find it. That is why I think the answer is A
