The answer is C - Various kinds of turtles
Step-by-step explanation:
The sentence which supports this answer is “is aimed at helping to conserve and protect the population of Olive Ridley Turtles in Costa Rica, although other species of turtles are also involved.” If you continue to listen to the audio you find that other species of turtles are also involved, but not all type of turtles. Thus options (a) and (b) are wrong answers.