Consider the following relationships among members of a family of six persons A, B, C, D, E and F:
1. The number of males equals that of females.
2. A and E are sons of F.
3. D is the mother of two, one boy and one girl.
4. B is the son of A.
5. There is only one married couple in the family at present

Which one of the following inferences can be drawn from the above?

Correct Option: A is the husband of D.

Step-by-Step Explanation:

Let us analyze the given statements step-by-step to deduce the relationships among the six family members: A, B, C, D, E, and F.

1. Identify the Gender of Members:

From statement 1: The total number of members is 6, and the number of males equals the number of females. Therefore, there are exactly 3 males and 3 females in the family.

From statement 2: "A and E are sons of F."
This tells us that A and E are male.

From statement 4: "B is the son of A."
This tells us that B is male.

Since A, B, and E are all males (total 3 males), the remaining three members (C, D, and F) must be females (total 3 females).

2. Analyze the Children and Relationships:

From statement 3: "D is the mother of two, one boy and one girl."
Since D is a mother, she is female (which matches our deduction). Her children consist of 1 boy and 1 girl.

We know F is female and has two sons, A and E.
Since F has two sons (both are boys), D's children (1 boy and 1 girl) cannot be A and E. Hence, F and D are two distinct mothers in the family.

3. Determine the Married Couple:

From statement 5: "There is only one married couple in the family at present."

Let's look at the generations:
- F has sons A and E.
- A has a son B.
- D has two children: 1 boy and 1 girl.

Since B is a boy and son of A, and D has one boy and one girl as her children, B must be the boy child of D. This means A and D are the parents of B and a girl child (which must be C, as C is the remaining female).

Therefore, A (male) and D (female) are married to each other, making A the husband of D.

Conclusion:

Evaluating the given inferences:
- "A, B and C are all females." - Incorrect (A and B are males).
- "A is the husband of D." - Correct.
- "E and F are children of D." - Incorrect (E is the son of F).
- "D is the daughter of F." - Incorrect (D is married to F's son, A).