In a Family Intelligence Show program, a couple and their son and daughter participated in an intelligence contest. The results showed that: [1] The first and third place have different genders. [2] The oldest member and The third place has a different gender. [3] The youngest member and the fourth place have a different gender. [4] The first place is older than the fourth place. [5] Father is the oldest member. [6] Second place  is not the youngest member.
the second place?
Son.