Step 1: Understanding the Concept:
Given the condition M=5, we need to find which of the statements can be true by finding at least one valid schedule that includes it.
Step 2: Key Formula or Approach:
Fix M=5 and N=3. Then, determine the possible arrangements for J, K, and L in the remaining slots (1, 2, 4) that satisfy the "at least 4 preferences" rule.
Step 3: Detailed Explanation:
1. We are given M=5 (preference) and we know N=3 (preference).
2. We need to place J, K, L in slots 1, 2, and 4.
3. We need at least two more preferences met. The preferences are L=1, K=2, J=1 or 2.
4. To get two preferences, we must use L=1 and K=2, OR L=1 and J=2.
- \textbfPossibility 1: L=1 (pref), K=2 (pref). This leaves J for slot 4 (not pref). Total preferences: L, K, N, M (4). The schedule is: L(1), K(2), N(3), J(4), M(5).
- \textbfPossibility 2: L=1 (pref), J=2 (pref). This leaves K for slot 4 (not pref, but acceptable). Total preferences: L, J, N, M (4). The schedule is: L(1), J(2), N(3), K(4), M(5).
5. Now we test the options against these two possible schedules:
- (A) J's appointment is 1. False in both possibilities.
- (B) N's appointment is 1. False, N is always 3.
- (C) J's appointment is earlier than K's. In Possibility 2, J is at 2 and K is at 4. So J is earlier than K. This can be true.
- (D) K's appointment is earlier than L's. False, L is always at 1 in these scenarios.
- (E) N's appointment is earlier than L's. False, L is at 1 and N is at 3.
Step 4: Final Answer:
The schedule L(1), J(2), N(3), K(4), M(5) is valid when M=5, and in this schedule, J's appointment is earlier than K's.