Task: Reasoning / Logical Reasoning
User instruction:
All three boys - Jake, Mark, and Henry - have one younger sister, each named Sara, Jenny, and Julia.
The six are playing badminton in mixed pairs, and no one can be partnered with their own sibling.
First game: Jake and Sara vs. Henry and Jenny
Second game: Henry and Julia vs. Jake and Mark’s sister
Who is the brother of Sara, Jenny, and Julia?

Evaluation criteria:
You must provide correct answers. Correct answers are as follows:
  - Henry’s younger sibling is Sara.
  - Mark’s younger sibling is Jenny.
  - Jake’s younger sibling is Julia.
If your answer includes a reasoning process, there must be no errors in that reasoning.