Answer
$$\bf{B}$
Work Step by Step
The area of a pentagon can be computed as:
$A=\dfrac{1}{4} \sqrt {5(5+2\sqrt 5)a^2}$
Here, we have $a=4 \ cm$
So, $A=\dfrac{1}{4} \sqrt {5(5+2\sqrt 5)(4)^2}=27.5 \ cm^2$
Therefore, the correct option is $\bf{B}$.
