It is D, sharing appreciation for what is being said. Both A and B aren't crucial to being a good listener, in fact in practice they effectively draw attention to yourself, which would be fine if the question was regarding being a good conversationalist. Additionally, C is just completely irrelevant, that wouldn't even be a good conversation practice, let alone a trait important to listening.
I think lifeguard if you already know how to swim then you don’t have to do any training. And I think being a chef because if you’ve been cooking for like 5 years or something then you don’t need any practice.
Answer:
set up a health clinic to help treat waterborn diseses :)
