How many different functional groups are present in the given compound?

A. $6$
B. $5$
C. $4$
D. $3$

Hint: In organic chemistry, the functional groups are the substituent groups of atoms which are bonded to the specific molecules. These parts of a molecule are responsible to undergo distinctive chemical reactions and account for the different characteristic chemical properties for those molecules.

Complete answer:
In the given compound, the functional groups present are represented as follows:

The name and general representation of the functional groups present are as follows:
1. Alcohol: It is generally represented as $R - OH$, where R represents the rest of the molecule and $OH$ represents a functional group.
2. Amine: It is generally represented as $R - N{H_2}$, where R represents the rest of the molecule and $N{H_2}$ represents a functional group.
3. Aldehyde: It is generally represented as $R - CHO$, where R represents the rest of the molecule and $CHO$ represents the aldehydic functional group.
4. Ketone: It is generally represented as follows:

Where, ${R_1}$ and ${R_2}$ represent different alkyl groups and $ - C = O$ represents ketonic functional groups.
5. Carboxylic acid: It is generally represented as $R - COOH$, where R represents the alkyl group or the rest of the molecule and $COOH$ represents the functional group.
6. Alkyne: It is generally represented as ${R_1} - C \equiv C - {R_2}$, where ${R_1}$ and ${R_2}$ represents different alkyl groups and $C \equiv C$ represents the functional group.
Hence, the total number of functional groups present in the given compound $ = 6$. So, option (A) is the correct answer.

Note:
It is important to know that alkanes are not considered as functional groups, in fact an alkane is a compound or a molecule which lacks functional groups due to presence of carbon-carbon single bond which consist of only sigma character that is much stronger and stable than alkenes and alkynes.