A function stretch if it was multiplied by a number higher than 1. Assuming the base number is 1, if it becomes 5 then it is stretched. If the number become 1/5(less than 1) it is called compressed.
Exponential decay function has ratio <1. Grah with 1/5^x would be decay and graph with 5^x would be growth.
The answer would be C. f(x)= 5 (1/5)^x
