I said to him, "How long will you stay?" He replied,"For five days." Which one of the following is the correct indirect from of above sentences ?

I asked him how long he will stay. He replied that he would stay for five days.

I asked him how long he would stay. He replied that he would stay for five days.

I ask him how long he would stay. He replied that he would stay for five days.

I asked him how long he would stay. He reply that he would stay for five days.