1. Correct Answer: Option D: 24
 2. Explanation:
     To solve this problem, we need to assign tasks to five persons: P, Q, R, S, and T, with the given constraints.
     Step 1: Identify the constraints.
         ○ Neither P nor Q can be assigned Task-1.
         ○ Task-2 must be assigned to either R or S.
     Step 2: Assign Task-2.
         ○ Task-2 can be assigned to either R or S. This gives us 2 choices.
     Step 3: Assign Task-1.
         ○ Since neither P nor Q can be assigned Task-1, Task-1 can be assigned to either R, S, or T. This gives us 3 choices.
     Step 4: Assign the remaining tasks.
         ○ After assigning Task-1 and Task-2, we have 3 tasks left to assign to 3 people. The number of ways to assign these tasks is 3! (factorial of 3), which equals 6.
     Step 5: Calculate the total number of ways.
         ○ Multiply the number of choices for each step:
           ○ Choices for Task-2: 2
           ○ Choices for Task-1: 3
           ○ Choices for remaining tasks: 6
     \[
     \text{Total number of ways} = 2 \times 3 \times 6 = 36
     \]
     However, we must consider that assigning Task-2 to R or S affects the choices for Task-1. If Task-2 is assigned to R, Task-1 can only be assigned to S or T, and vice versa. This adjustment reduces the number of choices for Task-1 from 3 to 2 in each scenario.
     Therefore, the correct calculation is:
     \[
     \text{Total number of ways} = 2 \times 2 \times 6 = 24
     \]
     Thus, the correct answer is Option D: 24.