The Decay Factor of an Exponential Function $P ( t )$

Multiple Choice

The decay factor of an exponential function $P ( t )$ is 0.2. The initial value is 1.15. Then a formula for P is

A) $P = 0.2 \times t ^ { 1.15 }$
B) $P = 0.2 \times 1.15 ^ { t }$
C) $P = 1.15 \times t ^ { 02 }$
D) $P = 1.15 \times 0.2 ^ { t }$