Read the sentence.

I had to prove my identity to gain entrance to the building I was required to fill out an impressive number of forms.

What is the best way to revise the sentence?


I had to prove my identity to gain entrance to the building, I was required to fill out an impressive number of forms.

I had to prove my identity to gain entrance to the building; I was required to fill out an impressive number of forms.

I had to prove my identity, to gain entrance to the building I was required to fill out an impressive number of forms.

I had to prove my identity: to gain entrance to the building I was required to fill out an impressive number of forms.