A Formula Is Given, Along with Values for All but One

Multiple Choice

A formula is given, along with values for all but one of the variables in the formula. Find the value of the variable that is not given.
- $I=p r t ; t=5, p=140, r=0.07$

A) $\mathrm{I}=4.802$
B) $I=0.5$
C) $\mathrm{I}=480.2$
D) $I=49$