Someone please help me!

A marine biologist is studying the growth of a particular species of fish. She writes the following equation to show the length of the fish, f(m), in cm, after m months:

f(m) = 3(1.09)m

Part A: When the marine biologist concluded her study, the length of the fish was approximately 5.98 cm. What is a reasonable domain to plot the growth function?

Part B: What does the y-intercept of the graph of the function f(m) represent?

Part C: What is the average rate of change of the function f(m) from m = 2 to m = 8, and what does it represent?