Step 1: Understanding the Concept:
Acidity depends on the stability of the conjugate base formed after losing a proton.
Step 2: Detailed Explanation:
\begin{itemize}
\item RCOOH (Carboxylic acids): Strongest among these due to resonance stabilization of carboxylate ion. pKa ≈ 4-5.
\item H\(_2\)CO\(_3\) (Carbonic acid): Weak acid, pKa ≈ 6.4.
\item C\(_6\)H\(_5\)OH (Phenol): Weak acid, pKa ≈ 10.
\item H\(_2\)O (Water): Very weak acid, pKa ≈ 15.7.
\item ROH (Alcohols): Very weak acid, pKa ≈ 16-18.
\end{itemize}
Step 3: Final Answer:
The correct order is RCOOH>H\(_2\)CO\(_3\)>C\(_6\)H\(_5\)OH>H\(_2\)O>ROH, option (A).