The base of the exponential function must be a positive number, then option C. it's not possible.
In the graph, when x=0, y=3
Option B it's not posiible because when x=0→F(0)=3^0→y=1
In the graph, when x=1, y is approximately 4
Option A it's not possible because when x=0→F(0)=3*(0.4)^1=3*0.4→y=1.2
It's option D, because when x=0→F(0)=3*(1.4)^1=3*1.4→y= 4.2
Answer: OPtion D. F(x)=3*(1.4)^x