Bring it.
Okay, the answer is dominant seventh. I wasn't sure if that was your official guess up above. You did mention it, so I will credit you with it since you were the only one. No one else brought up that chord.
Explanation: In set theory, you count the smallest intervals first. Bottom note is zero, and half steps go up by one. So a minor triad is (0,3,7) A major triad is also (0,3,7) because you count the smallest intervals first. In a minor triad, the smaller interval is on the bottom; in a major triad it's on top. But either way, the two chords have an identical pitch class set.
Half diminised seventh chord is (0,2,5,8) Dominant seventh chord is also (0,2,5,8) You have to put the chord so the outer voices are as close together as possible, and start with the smallest interval. So the dom 7 chord would be in 6/5 inversion.
How could you see this without set theory? Just realize in a minor triad, the intervals go in reverse order from a major triad. I in a half dim seventh chord, the intervals go in reverse order to the dominant seventh.
This is one of the first things you learn in set theory, so people who have taken the class know this. I wasn't just being an esoteric jerk or anything.