Step 1: Alkene Hydrogenation.
Alkene (C) is hydrogenated with H\(_2\) and Ni to yield saturated compound (A).
Step 2: Esterification.
Compound (A) reacts with benzoic acid (\(PhCO_2H\)) and water via esterification to form (B).
Step 3: Nucleophilic Substitution.
Ester (B) undergoes nucleophilic substitution with ethanol (\(EtO\)) to produce (C).
Step 4: Grignard Reaction.
Compound (C) reacts with ethylmagnesium bromide (EtMgBr) in anhydrous ether, followed by aqueous work-up, to yield 2-butanol (D).
Final Answer: \[\boxed{\text{(2) 2-Butanol}}\]