Determine weather each function represents exponential growth or exponential decay function

The exponential function is represented by
[tex]y=ab^x[/tex]if a is positive and b is greater than 1 then it's an exponential growth
But if a is positive and b is less than 0, then is an exponential Decay.
A is DECAY
B is GROWTH
C is GROWTH
D is DECAY
E is DECAY