Which sentence is written correctly?

Its about to escape because it's leash is so loose.

It's about to escape because its' leash is so loose.

Its about to escape because its leash is so loose.

It's about to escape because its leash is so loose.

Its about to escape because it's leash is so loose

I believe the answer is "It's about to escape because its' leash is so loose" because the first form shows "it's" which means "it is", which is the correct form, so you're left with two options and when you look at b, " its' " shows ownership, so it would have to be that one.