Answer:
A. 9 months
Explanation:
We are given that,
Initial members in the club = 350
Rate of growth of the members = 4% = 0.04
Since, the exponential growth function is given by
, where a= initial value and r= rate of increase and x= time.
Substituting the values, we have,
Number of increase in the members after 'x' months is,

Now, the number of months when the number of members is 500 is,

That is, after 9 months, the number of members will be 500.
So, option A is correct.