Need answer fast

one year after a tree is planted, the tree is 3.5 ft tall. each year, the tree grows 1.5 ft. what function, written in sequence notation, models the height of the tree n years after it is planted?

a. an=3.5n+1.5

b an=1.5n+3.5

c. an=1.5n+2

d. an=5n+1.5