In a group of five friends: Alice, Bob, Charlie, David, and Eva, Alice and Bob cannot be selected together. Charlie can only be selected if David is also selected. Eva can be selected only if Charlie is not selected. Which of the following combinations can be selected?
In a race, five participants A, B, C, D, and E finish in the following order: A finishes before B but after C. D finishes before E but after B. What is the correct finishing order?
A group of students: 1, 2, 3, 4, and 5 must be selected based on these rules: 1 and 2 cannot be selected together. 3 must be selected if 4 is selected. 5 can be selected only if 3 is selected. Which of the following selections is valid?