- Step 1: Valid arrangements: T1, T2, T3, T4 or T1, T2, T4, T3.
- Step 2: Slot 4: T4 in first, T3 in second.
- Step 3: T2 cannot be in 4. T4 is common in slot 4 due to “after T2â€.
- Step 4: Verify T1, T2, T3, T4: Slot 4 = T4.
- Step 5: Check options: Option (4) is T4, which matches.
- Step 6: Ensure constraints are met.