Answer:
Option (a) is correct.
The Juan’s initial investment is $ 5
Explanation:
Given : Juan’s investment account can be modeled by the function,
 , in thousands of dollars.
, in thousands of dollars. 
We have to find the Juan’s initial investment.
Since, Juan’s investment is modeled by function 

Since initial investment is when he start the investment and is given by when 
x = 0 
Thus, 

Simplify , we get, 
c(0) = 5 
Thus, the Juan’s initial investment is $ 5