Fill in the blank (_) in the following sentence from the following choices.
Sentence: Donald asked Christopher on how to heal a sprained ankle but _ was clueless on the topic.

Choice 1: Donald asked Christopher on how to heal a sprained ankle but Donald was clueless on the topic.
Choice 2: Donald asked Christopher on how to heal a sprained ankle but Christopher was clueless on the topic.
Which of the choices is correct? Respond with only "1" or "2" and no additional text.
2
2.