In the following sequence of reactions, the P is:

Step 1: Identify the starting material and reaction sequence

The reaction sequence involves a cyclopentane derivative undergoing transformations to produce P.

Step 2: Trace the reaction sequence

Based on the reaction sequence shown:

1. Starting alkyl halide undergoes treatment to give an intermediate
2. The intermediate undergoes further reaction
3. The final product P is a cyclopentane ring compound

Step 3: Identify product P

The reaction sequence converts the starting material through:

• First step: Grignard reagent formation or elimination
• Subsequent steps lead to ring formation/reduction

The product cyclopentane ($\ce{C5H10}$) results from the complete reduction/cyclization sequence. The saturated cyclopentane ring is the final product P.

Answer: Option (d) — Cyclopentane

Key Points to Remember:

• Cyclopentane is a stable 5-membered ring with minimal angle strain
• Ring-forming reactions often proceed via intramolecular nucleophilic substitution
• Reduction of cyclopentene gives cyclopentane