Looking at the picture on the wall, he said "My sister-in-law S's husband Q's son N had a sister R". How is S related to R?

To determine the relationship between S and R based on the statement: "My sister-in-law S's husband Q's son N had a sister R," we can break down the relationships step by step. • S is the sister-in-law of the speaker, implying that S is married to the speaker's brother (Q). • Q is S's husband. • N is Q's son, making N the son of S as well, since N and R are siblings. • R is N's sister, which means R is also S's daughter because R is the sibling of S's son N. Therefore, S is related to R as R's mother. The correct answer is: 4. Mother