Answer:
[tex]\begin{aligned}\textsf{D.}\quad 2x + 5y &= 23\\3x + 3y &= 21\end{aligned}[/tex]
Step-by-step explanation:
Definition of variables:
Given information:
Therefore, the system of equations that can be used to determine the price of a chocolate chip cookie and the price of an oatmeal cookie is:
[tex]\large\boxed{\begin{aligned}2x + 5y &= 23\\3x + 3y&= 21\end{aligned}}[/tex]