Quick Solution

The best way to solve this blood relation puzzle is to draw a family tree based on the clues provided, and then check each statement to see if it must be true.

1. Building the Family Tree

• "C is wife of B and mother of F" tells us B (male) and C (female) are a married couple with a child, F.
• "D is mother of B" makes D the paternal grandmother. We also know F is a female ("granddaughter").
• "F is the grand daughter of E" means E must be the other grandparent. Since D is B's mother, E must be B's father. This makes (E, D) the first married couple.
• "D is grandmother of A" means A must also be a child of B and C, and therefore a sibling of F.

This gives us the following family structure:

2. Evaluating the Statements

The key finding from building the family tree is that the gender of child A is unknown. A could be a boy or a girl. With this in mind, let's check the options:

• A. A is brother of F. This statement is only true if A is male. Since we cannot be certain of A's gender, we cannot confirm this statement.
• B. A is sister of F. This statement is only true if A is female. Again, we cannot be certain.
• C. B has two daughters. This is only true if A is female. We know F is a daughter, but we don't know about A. We cannot confirm this statement.

Since none of the statements A, B, or C can be definitively proven to be true with the given information, the correct conclusion is "None of these".

Final Answer: None of these statements is verifiably true.