An antiseptic dettol is a mixture of two compounds 'A' and 'B' where A has $$6\pi$$ electrons and B has $$2\pi$$ electrons. What is B?

Dettol is an antiseptic that contains a mixture of chloroxylenol and terpineol.

Chloroxylenol (4-chloro-3,5-dimethylphenol) is an aromatic compound. The benzene ring contains $$6\pi$$ electrons. So compound A is chloroxylenol.

Terpineol is a monoterpene alcohol with the molecular formula $$C_{10}H_{18}O$$. It contains one carbon-carbon double bond ($$C=C$$), which contributes $$2\pi$$ electrons. So compound B is terpineol.

Verification:

Chloroxylenol has an aromatic ring with $$6\pi$$ electrons — matches A.

Terpineol has one $$C=C$$ double bond with $$2\pi$$ electrons — matches B.

The correct answer is Option B: Terpineol.