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.
- $\mathrm{A}=\frac{1}{2}(\mathrm{~b}+\mathrm{B}) \mathrm{h} ; \mathrm{h}=8, \mathrm{~b}=14, \mathrm{~B}=10$

A) $\mathrm{A}=72$
B) $\mathrm{A}=12$
C) $\mathrm{A}=140$
D) $\mathrm{A}=96$