To find the total area of the town of Oak Manor, you multiply the length by the width:
\[ \text{Area} = \text{Length} \times \text{Width} = 3.8 , \text{mi} \times 4.2 , \text{mi} \]
Calculating this:
\[ 3.8 \times 4.2 = 15.96 , \text{square miles} \]
Thus, the total area of Oak Manor is 15.96 square miles.
Based on the options you've provided, the correct answer is B) 15.96 MIĀ².