We can immediately eliminate B & C.
B is showing decay and C is growing but rate of growth slows down after a while to negligible amount.
Both A and D are showing growth but we want PURE EXPONENTIAL GROWTH.
A is growing exponentially but after a certain while, whereas D is exponentially growing from the start. This is pure exponential growth. So our answer is the graph of D.
ANSWER: The graph in D is showing pure exponential growth.
