Choose the sentence with the correct use of a contrastive conjunction.

A. We could go to the park, or we can have a picnic in the backyard.

B. She must eat her vegetables before she can have dessert, and she needs to brush her teeth after.

C. He might buy a new phone, or he can wait until the next model is released.

D. They should go to the beach because it’s sunny, but they might stay home because they’re tired.