Read the following context and choose the best option to answer the question.
Context: A fruit plate was apparently requisite for any reputable snorkeling tour . We swam out in the direction that Carlos had suggested . We did n't really see new coral that we had n't seen before , but it was a good area , spectacular with coral growth . The types we saw : brain , lettuce leaf , fan , mustard hill and a few others that we did n't learn the names of , like one with purple fingers .
Question: What may be the reason that they are diving ?
Options: 
A. They wanted to get photos of the reefs .
B. None of the above choices .
C. They wanted to observe the coral reef .
D. They were on a vacation .


C