Data Sufficiency — Relationships: How is X related to Y? Statement I: Y says, "I have only one brother." Statement II: X says, "I have only one sister." Decide which statements are sufficient to answer the question. Choose the correct sufficiency option.

Difficulty: Easy

• Statement I alone is sufficient, but Statement II alone is not sufficient.
• Statement II alone is sufficient, but Statement I alone is not sufficient.
• Both statements I and II together are sufficient, but neither alone is sufficient.
• Either statement I or statement II alone is sufficient.
• Even both statements I and II together are not sufficient.