The given statement can be interpreted as:
\[
\text{If a student scores more than \(50\%\) marks (\(q\)), then a fail grade (\(p\)) cannot be given (\(\neg p\)).}
\]
This can be directly represented in propositional logic as:
\[
q \to \neg p
\]
Validation of options:
(A) \(q \to \neg p\): Correct. Matches the interpretation of the given statement.
(B) \(q \to p\): Incorrect. This implies that scoring \(>50\%\) leads to a fail grade.
(C) \(p \to q\): Incorrect. This implies that failing implies scoring \(>50\%\), which is incorrect.
(D) \(\neg p \to q\): Incorrect. This implies that not failing implies scoring \(>50\%\), which is not equivalent to the given statement.
Final Answer:
\[
\boxed{q \to \neg p}
\]