Please I will give brainliest and 25 points. HELP ME! Which of the following can be modeled with a linear function? Select all that apply.

a. The cost per visit to a community pool. The neighborhood charges a yearly fee to use the pool.

b. The cost to attend a show at the local theatre. Tickets are $12 each.

c. An endangered species population is decreasing by 15% each year.

d. The distance a bicyclist travels when cycling at a constant speed of 30 mph.

e. The population of a town growing at a constant rate each year.

PLEASE HELP!