In base vs. Acid titration, at the end point methyl orange is present as

Methyl orange is an azo dye indicator used in acid-base titrations. It exists in two structural forms depending on the pH:

In acidic medium (pH < 3.1): Methyl orange exists in the quinonoid form, which is red/pink in colour.

In basic medium (pH > 4.4): Methyl orange exists in the benzenoid (azo) form, which is yellow in colour.

In a base vs. acid titration (i.e., titrating a base with an acid), at the end point, the solution becomes slightly acidic. Methyl orange changes from yellow to orange/pink at the end point.

At the end point, methyl orange is present in the quinonoid form.

Therefore, the correct answer is Option A.