Which functional group is present in a molecule of \[C{H_3}OH\]
(A) Ketone
(B) Aldehyde
(C) Ester
(D) Alcohol
(E) Halide

Hint: Functional groups are a type of molecules that carry certain characteristic properties. They get linked to other molecules, but do not move away from their true nature. They get linked to other molecules by either ionic or covalent bonds.

Complete Step-by-Step Solution:
In order to understand which functional group is present in a molecule of \[C{H_3}OH\], let us first discuss all the options:
1. Ketone: A ketone is a functional group in which a secondary carbon of any compound is attached with an oxygen atom. Since the oxygen atom has only one carbon to satisfy its oxidation state, it forms a double bond with this carbon. The general representation of a ketone is (R-O-R’):

Where R and R’ are alkyl or aryl groups. The double bonded oxygen is also known as the carbonyl group.
2. Aldehyde: An Aldehyde is a functional group in which a primary carbon of any compound is attached with an oxygen atom. To put it in simpler terms, the carbonyl group is attached to the terminal carbon. The general representation of an aldehyde is (R-CHO):

3. Ester: An ester is a functional group, in which the hydrogen atom from the carboxylic acid is substituted by another alkyl group. The general representation of an ester is (R-COOR’):

4. Alcohol: alcohol functional group consists of an oxygen and a hydrogen atom bonded together. They link to any compound through the oxygen atom and are commonly known as the hydroxyl group. The general representation of an alcohol is (R-OH):

5. Halide: halide means the functional group is just the element which is a halogen. The general representation of a halide is (R-X), where X is the halide:

Hence from this data, we can conclude that a functional group is present in a molecule of alcohol.

Hence, Option D is the correct option.

Note: Each type of organic molecule has its own specific type of functional group. Functional groups in biological molecules play an important role in the formation of molecules like DNA, proteins, carbohydrates, and lipids. Functional groups include hydroxyl, methyl, carbonyl, carboxyl, amino, phosphate, and sulfhydryl.