Concept:
This is a vocabulary-based “EXCEPT” question.
The word:
\[
\text{cavalier}
\]
usually means careless, dismissive, arrogant, or showing lack of proper concern.
Step 1: Understand the meaning of cavalier.
A cavalier attitude means an attitude that is:
\[
\text{careless}
\]
\[
\text{rash}
\]
\[
\text{dismissive}
\]
\[
\text{not serious}
\]
It may also suggest arrogance or haughtiness.
Step 2: Check the options.
Option (A) Haughty means arrogant, so it can match the sense of cavalier.
Option (B) Rash means careless or impulsive, so it can match.
Option (D) Frenetic means frantic or wildly excited. It may be related to uncontrolled behavior.
Option (C) Prudent means careful, wise, and sensible.
Prudent is opposite to careless or rash.
Step 3: Select the EXCEPT option.
Since “prudent” does not match the meaning of “cavalier”, it is the correct EXCEPT option.
Hence, the correct answer is:
\[
\boxed{(C)\ \text{Prudent}}
\]