A conductor is scheduling five musical pieces—Opus 1 (O1), Opus 2 (O2), Opus 3 (O3), Opus 4 (O4), and Opus 5 (O5)—for a concert. Each piece will be played exactly once, one after another. The following conditions govern their order: 1. Opus 3 must be played immediately after Opus 1. 2. Opus 5 must be played at some point after Opus 2. 3. Opus 4 cannot be played first. 4. Opus 2 cannot be played last. Which of the following is a complete and accurate list of the pieces that could be played first?

Correct answer: D. O1, O2, O5

Let's analyze each piece's possibility for the first position: * **O1:** If O1 is first, then O3 must be second (Rule 1). O2, O4, O5 remain. O5 after O2 (Rule 2). O4 not first (Rule 3) is satisfied. O2 not last (Rule 4) is possible. Example: O1-O3-O2-O4-O5. So, O1 can be first. * **O2:** If O2 is first, then O5 must be played later (Rule 2). O4 is not first (Rule 3) is satisfied. O2 is not last (Rule 4) is satisfied. O1 and O3 must be together (Rule 1). Example: O2-O1-O3-O4-O5. So, O2 can be first. * **O3:** If O3 is first, Rule 1 (O3 immediately after O1) is violated, as O1 cannot precede O3. So, O3 cannot be first. * **O4:** Rule 3 explicitly states O4 cannot be played first. So, O4 cannot be first. * **O5:** If O5 is first, Rule 2 (O5 after O2) is violated, as O2 cannot precede O5. So, O5 cannot be first. Therefore, only O1 and O2 can be played first. This means the correct list is O1, O2.