Exponential growth is when numbers increase rapidly in an exponential fashion so for every x-value on a graph there is a larger y-value. Decay is when numbers decrease rapidly in an exponential fashion so for every x-value on a graph there is a smaller y-value. So here the one that fits the description is A.
Hi! i believe the answer is a, because if b (in this case 0.2) is less than 1 and greater than 0 its exponential decay!! good luck with the rest of your hw and i hope this helps