Identify the most likely cause of the following scenario: A street in a desert is filled with cracks despite rarely being driven on by cars.
The asphalt is cracked from constant expanding due to heat during the day and contracting due to cold at night.
The asphalt is cracked due to animals burrowing to create homes.
The asphalt is cracked due to roots growing underneath from the lush rain forest surrounding the road.
The asphalt is cracked due to rusting caused by exposure to water and oxygen over long periods of time.