Which is a stretch of an exponential decay function?
A
f of x is equal to 4 fifths times 4 fifths to the x th powerB
f of x is equal to 4 fifths times 5 fourths to the x th powerC
f of x is equal to 5 fourths times 5 fourths to the x th powerD
f of x is equal to 5 fourths times 4 fifths to the x th power