Explanation: If N and O are not displayed, we need 3 CDs from {K, L, M} and 2 DVDs from {R, S, T, U}. Since K is an option and K \(\implies\) U (Condition 1), U must be displayed. Since U is displayed, S cannot be displayed (Condition 4). So DVDs must be {T, U}. We need 3 CDs from {K, L, M}. If M is displayed, then L and R must also be displayed (Condition 2). If M is displayed, the CD set must be {K, L, M} and the DVD set {R, T, U}. But we only need 2 DVDs, so the only one to display is R. This contradicts the selection of {T, U}. Therefore, M cannot be displayed. If M is not displayed, the 3 CDs must be {K, L, N} or {K, N, O} or {L, N, O} (but N and O are excluded), or {K, L}. Since N and O are excluded, and M is excluded, the CD set must be {K, L}. But we need 3 CDs. There is an error in the question or options as per the logic. Assuming the core selection must be K, L, M for the CDs since N and O are ruled out and M requires L. If N and O are excluded, K, L, M are the only CDs remaining (3 CDs). M \(\implies\) L and R. So, {K, L, M} and R. K \(\implies\) U. So, {K, L, M} and {R, U}. The set is {K, L, M, R, U}. This is 3 CDs and 2 DVDs (R, U). All items in this set must be displayed. T is the only one not in the set. (The question's intended logic leads to the set {K, L, M, R, U} as the required display items, leaving T out).
