premise: A rowing team uses a boat with exactly six seats arranged in single file and numbered sequentially 1 through 6, from the front of the boat to the back. Six athletes—Lee, Miller, Ovitz, Singh, Valerio, and Zita—each row at exactly one of the seats. The following restrictions must apply: Miller rows closer to the front than Singh. Singh rows closer to the front than both Lee and Valerio. Valerio and Zita each row closer to the front than Ovitz. Exactly how many different seats could be the seat occupied by Zita?
hypothesis: six