Number 3 is the only one that is correct.
Numbers 1 and 2 may be confusing to you because the subject isn't actually stated. The subject in both sentences is the understood "you."
(You) come to the state fair.
(You) notice the color of its feathers.
What is the simple subject in the following questions?
1. Come to the state fair.
2. Notice the color of its feathers.
3. Alan's prize rooster is there.
I think the answers are the following.
1. fair
2. its
3. rooster
Am I correct?
1 answer
1 answer