Please choose the correct answer to the question: A frog was sick because it wasn't staying warm enough.

Answer1: The frog was getting burned by a heat lamp Answer2: The water in the tank had dried up. Answer3: the frog was unable to regulate its body temperature without an external heat source Answer4: The frog was using too much ice in its drinks

Answer format: answer1/answer2/answer3/answer4
Answer: answer3