Answer:
B
Step-by-step explanation:
The best - well, only way- is to check a few points.
Namely -1 (unless your eyesight is really poor!), 0, 1, 2, and 3.
[tex]f(x) = 2^x\\f(-1) = 2^-^1 = \frac12\\f(0) =2^0 =1\\f(1)= 2^1=2\\f(2)=2^2=4\\f(3)=2^3= 8[/tex]
Now you can mark all these points in each graph (well, you could if they were on paper and not on a screen) and see which one of the lines passes through all of them. Spoiler alert, it's the B graph.
A represents [tex]2(2^x) = 2^{x+1}[/tex], B is the one you want, C is [tex]\frac{2^x}2 = 2^{x-1}[/tex] and D looks like [tex]4^x = 2^2^x[/tex]
