Which of the following can be modeled by a linear function?

A taxi driver charges $3.50 per ride and $0.80 per mile driven.

The relationship between the height of a ball after being kicked from the ground and the distance the ball is from the kicker.

The balance in a savings account that acquires 0.7% interest compounded monthly.

The relationship between the time passed and the speed of a car as it slows down for a curve then accelerates back to its regular speed.