Question

The answer is D, but I need help showing work.

Answer 1

$\begin{gathered} a_{n=16+5n} \\ at\text{ n=1} \\ a_1=16+5 \\ a_1=21 \\ a_2=16+5\times2 \\ a_2=26 \\ a_3=16+5\times3 \\ a_3=31 \\ a_4=16+5\times4 \\ a_4=36 \end{gathered}$