b
Vanillin compound is an organic compound molecular formula \(\mathrm{C}_3 \mathrm{H}_5 \mathrm{O}_3\). It is a phenolic aldehyde. Its functional compounds include aldehyde, hydroxyl and ether. It is the primary component of the extract of the vanilla beans.

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Total sum of oxygen atoms and \(\pi\)-electrons is \(3+8=11\)

Total number of oxygen atoms \(=3\)

Total number of \(\pi\)-bonds \(=4\)

\(\therefore\) Total number of \(\pi\)-electrons \(=8\)