Explanation:

Let’s break this down with each statement and see who’s who:

- A is the engineer, married to the lady stenographer (let’s label her B for now).

- The judge is married to the lawyer (so, another couple—note that).

- F is the draughtsman, son of B, brother of E.

- C is the lawyer and the daughter-in-law of D.

- E is the unmarried doctor (can’t be part of a couple).

- D is the grandmother of F.

- Two married couples in the family.

Let's assign everyone:

- If A is the engineer (male), married to the stenographer (lady), who is B. Couple one: A and B.

- The judge is married to the lawyer. C is the lawyer and daughter-in-law of D. So, C (lawyer, female) is married to someone who could be the judge (her husband). That’s not A (he’s the engineer)—must be E or F. E is unmarried, so F’s the son, so F’s too young or unmarried. It must be A married to C. But wait, that can't be because A is with the stenographer. So, maybe B is the judge, C is the lawyer (female), her husband can only be B. But B is the lady stenographer.

Let’s build the family:

- D (grandmother)

- A (engineer, married to B the stenographer)

- B (A’s wife, stenographer)

- F (son of B, draughtsman, brother of E)

- E (unmarried doctor, sibling—so likely daughter)

- C (lawyer, daughter-in-law of D, must be married to A or F)

- A & B = Couple 1

- Judge is married to the Lawyer. The only people left to pair as a couple are D (grandmother) and someone else, but D is the grandmother and C is her daughter-in-law. So, D is married to someone not mentioned directly. Only two married couples are A-B and the judge-lawyer pair. Since E is unmarried, F is the son. C is the lawyer married to A or F.

But F is the son, so can’t be married. So, A is married to C (lawyer), so B is the stenographer, D is grandmother (not part of a couple anymore). So, only married couples are A and B, and Judge and Lawyer (A-C). But, since only two married couples—and the passage says A is married to the lady stenographer, and the judge is married to the lawyer—then A is with B, someone else (Judge, not specified) is married to the lawyer (C). So, couples are A-B and Judge-Lawyer (C and another).

Now, your options:

1. Only AD

2. Only BC

3. AD and BC

4. AC and BD

Here’s the thing: None of the names matches the actual correct couple pairing according to the information. But the passage's couples are *A & B* and *Judge (unidentified) & C*, but in the options, none reflect that.

To summarize:

- A and B are definitely a couple (engineer and stenographer)

- Judge and C (lawyer) are a couple, but options don’t match that pairing

- AD is not a couple.

None of the options are quite a perfect fit, but AD is definitely not a couple.

If I missed something and you think AD refers to A married to D (but D is the grandmother), that would be incorrect because A is married to B.