Ответ:

А

1) Has your mum already made a tasty dinner?

2) Who has already made a tasty dinner?

3) has your mum already made a tasty dinner or not tasty?

4) your mum already made tasty dinner, has she?

B

1) have the children cleaned their room?

2)who have just cleaned their room?

3)have the children just cleaned their room or garden?

4)the children have just cleaned their room, have they?