A group of students: Alex, Ben, Clara, Diana, and Ethan are to be selected based on the following conditions: 1) At least two students must be selected. 2) Alex and Ben cannot be selected together. 3) Clara must be included if Diana is included. Which of the following selections is valid?

Answer: A. Alex, Clara, Ethan
Alex and Clara can be selected together with Ethan, satisfying all conditions.