Given a formula of a functional group: An organic compound that has this functional group is classified as 1) an organic acid 2) an ester 3) a ketone 4) an aldehyde

Since the formula of the functional group is not given in the question, here are possible answers; If it is;

1. -COOH or -CO2H, it is an organic acid

2. -COOR, it is an ester

3. RC=O, it is a ketone

4. HC=O, it is an aldehyde

Note: Check the attachment below

Explanation:

The functional group of an organic compound is a specific group of atoms or bonds within a compound that is responsible for the characteristic chemical reactions of that compound.

The most common functional groups are:

Carbonyls (C=O); which includes the aldehydes, HC=O, and ketones, RC=O

Alcohols (-OH),

Carboxylic (organic) acids (COOH),

Edters (COOR), and

Amines (NH2).

the positions which points up in upward carbon and down in downward carbon are axial

and vice versa holds true for equatorial positions

so the correct answer with labelled diagram will be

it is the most commonly accepted one