Question

If I owned a big house in the country, I _____ lots of animals to roam around freely. 1. will have bought 2. shall have bought 3. have bought 4. would buy'

Answer 1

The answer would be 4. would buy. #4 is the answer because it makes the most sense.

Answer 2

it states that IF you bought it, so you haven't yet.
Only "would buy" will make any sense. it means you WILL, not that you have or shall.