Consider the differential equation
$y^{\prime \prime}+p y^{\prime}+q y=0$
where $p$ and $q$ are constants, $p^2=4 q$, and $q \neq 0$. If $y$ is a nonzero solution of the equation, then which of the following statements is correct?

• Correct answer
  A

  $y^2$ can never be a solution.
• B

  $y^{\prime}$ can never be a solution.
• C

  $(1+x) y$ can never be a solution.
• D

  $x y$ can never be a solution.

Hence, the correct answer is option: 'A'.