Identify sequential reactions involved in Sol-Gel process .

The sol-gel process involves two sequential reactions for producing solid materials from molecular precursors.

Hydrolysis replaces alkoxy groups with hydroxyl groups:
$\mathrm{M(OR)_n + xH_2 O \rightarrow M(OH)_x(OR)_{n-x} + xROH}$

Polycondensation follows, forming metal-oxygen-metal bridges through either olation/oxolation or esterification:
$\mathrm{M-OH + HO-M \rightarrow M-O-M + H_2 O}$
$\mathrm{M-OR + HO-M \rightarrow M-O-M + ROH}$

This sequence establishes the correct order as hydrolysis followed by polycondensation, corresponding to option B.