collocation and tag

[maoyueh]

Please help me with the following questions, thank you a lot.

1. I think it is illogical to say "enter the door." It would be better to say "enter the house/room/etc.," or "enter through the door." Please correct me if I am wrong.

2. Dad said you are a good boy, (A. didn't he B. aren't you)? Which one should I choose?

3. Dad said the movie was interesting, (A. didn't he B. wasn't it)? Which one should I choose?

[Rover_KE]

1. You are correct.

2 and 3. Tell us what you think first and why.

Rover

[maoyueh]

1. You are correct.

2 and 3. Tell us what you think first and why.

Rover

Thank you for your help.
Some grammar books say that the answers to questions 2 and 3 should be A, but to my mind, both A and B are correct. Please correct me again if I am wrong.

[Rover_KE]

A is correct in both cases. The tag question refers back to the main verb: 'Dad said...didn't he?'

Rover