Humans have two feet so they have to buy shoes in pairs.is the reasoning for what question and answer pair?

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Q: Most humans by shoes in pairs, this is because they happen to have what?
Options:
- two ears
- lay eggs
- one head
- a bad day
- two feet
A: two feet