Chemistry Question from JEE Main 2023 · 30 January, Shift 1

A trisubstituted compound ‘A’, $C_{10}H_{12}O_2$, gives neutral FeCl$_3$ test positive. Treatment of compound ‘A’ with NaOH and CH$_3$Br gives $C_{11}H_{14}O_2$, with hydroiodic acid gives methyl iodide and with hot conc. NaOH gives a compound ‘B’, $C_{10}H_{12}O_2$. Compound ‘A’ also decolourises alkaline KMnO$_4$. The number of $\pi$ bond/s present in the compound ‘A’ is _____.