Two Americans are going. One is father of the son of the other. What is the relationship between the two?

Answer: D) Husband-Wife. Let the two people be X and Y. The statement says X is the father of Y's son, so Y's son is X's child. That means Y is the other parent of that child, which makes Y X's spouse. Since X is the father of Y's son, X is male and Y is female, so they are husband and wife.

• A) Father-Son: Wrong. If Y were X's son, Y's son would be X's grandson, not X's son.
• B) Mother-Son: Wrong. The statement makes X the father, so X cannot be the mother.
• C) Mother-Daughter: Wrong. This would make X the mother of Y's son, which contradicts the father clue, and it does not fit the spouse relationship.

Core concept: blood relations versus marital relations. Logical reasoning and kinship questions of this kind test whether you trace who is the parent of whom, rather than guessing from the surface words. This also shows up in Mains ethics and social-structure answers where family roles matter.

Trap: Reading "father of the son of the other" as a direct line of descent and picking Father-Son.