The major product of the following reaction is:

The reaction sequence can be understood by following the transformation of the functional group at each stage.

In the first step, 4-methylpentanoyl chloride reacts with alcoholic ammonia.

This is a nucleophilic acyl substitution reaction in which ammonia attacks the carbonyl carbon and replaces the chloride ion, producing the corresponding primary amide.

Thus, the first intermediate formed is

$$\boxed{\mathrm{CH_3-CH(CH_3)-CH_2-CH_2-CONH_2},}$$

which is 4-methylpentanamide.

In the second step, the amide is treated with

$$\mathrm{Br_2/NaOH}.$$

These reagents carry out the Hoffmann bromamide degradation, converting a primary amide into a primary amine containing one carbon atom less than the original amide.

The carbonyl carbon is eliminated during the reaction.

Hence, the second intermediate is

$$\boxed{\mathrm{CH_3-CH(CH_3)-CH_2-CH_2-NH_2},}$$

which is 3-methylbutan-1-amine.

In the third step, the primary aliphatic amine is treated with

$$\mathrm{NaNO_2/HCl},$$

which generates nitrous acid in situ.

The amine undergoes diazotization to form an unstable aliphatic diazonium salt. This intermediate immediately loses nitrogen gas to produce a carbocation.

In the presence of water, the carbocation is attacked by a water molecule, resulting in hydrolysis to the corresponding alcohol.

Therefore, the final product obtained is

$$\boxed{\mathrm{CH_3-CH(CH_3)-CH_2-CH_2-OH},}$$

which is 3-methylbutan-1-ol.

Hence, the correct answer is

$$\boxed{\text{Option (C).}}$$