Which one is right for this please

Part A:
The function that will be used to model the situation is exponential function, This is because the increment in the values of the the investment are not linear increment. The appropriate function is exponential function.

Part B.
Exponential function is given by:
y=a(b)^x
where:
a= initial value
b=growth factor
thus
for Option A:
a=1100
b=1210/1100=1.1
thus the function will be:
y=1100(1.1)^x

for option B
a=1100
b=1200/1100=1.091
then
y=1100(1.091)^x

Part C
Suppose Belinda invested in :
Option A, the value after 20 years will be:
y=1100(1.1)^20
y=7400.25

Option B, the value after 20 years will be:
y=1100(1.091)^20
y=6278.96

thus option A has a greater value