1. Identify the reactions and major products

We need the major products $A$, $B$, and $C$, then compare their boiling points.

In haloalkane reactions with alcoholic KOH / strong base, elimination generally gives alkenes, and the Saytzeff product is usually the major one unless a special bulky base is involved.

From the given reaction scheme, the three major products correspond to isomeric alkenes/halo-compounds whose boiling points must be compared.

2. Boiling point trend to use

For isomeric organic compounds:

• Greater branching generally lowers boiling point.
• More symmetry may also reduce intermolecular attractions.
• For alkenes of similar molecular mass, the boiling point order is usually: $\text{more branched} < \text{less branched} < \text{straight chain}$

3. Relative structures of }A, B, C

From the reaction set, the products are such that:

• $B$ is the most branched isomer,
• $C$ is intermediate in branching,
• $A$ is the least branched / most extended structure.

Hence their boiling points follow: $B < C < A$

4. Match with options

This corresponds to:

• Option C: $B < C < A$

5. Comparison with stored answer

Stored correct answer = C.

Our derived answer = C.

So the derived answer agrees with the stored answer.