I-539 question:urgent F1(OPT) TO H4

I am applying changing status from F1 opt to H4,
Spouse's H1B was approved this March.

I have some question on I-539:

1 part.1 "Address in care of ", what does this mean?

2 part.3 line.2 and line 3, don't quite understand. Yes or no for mycase.

3. part 4 a and b. how to fill? (my status history is F2-F1- H4).





Thanks for your answer