C. Training Max was challenging because... 1) there were no classes for pets. 2) he was curious. 3) he didn't like other dogs. 4) he refused to learn commands.

Question

Вопрос:

Accepted Answer

Текст гласит, что команда "оставь" (leave it) давалась Максу с трудом, потому что он был естественно любопытным.

Ответ: 2) he was curious.