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