In a school, the following codes were used during a physical exercise. 'l' means 'start walking', '2' means 'keep standing', 3' means 'start running at the same spot', '4' means 'sit down'. How many times will a student who performs the following sequence without error from the beginning to the end have to sit down?
1 2 3 4 2 3 1 4 4 3 2 2 1 2 4 3 1 4 4 1 2

Options

A. 2
B. 3
C. 4
D. 5

Explanation

To solve the problem, we need to count how many times the code '4', which means 'sit down', appears in the given sequence of codes.

The sequence provided is:
1 2 3 4 2 3 1 4 4 3 2 2 1 2 4 3 1 4 4 1 2

### Step-by-Step Solution:

1. **Identify the Sequence**: Write down the entire sequence of codes as given:
- 1 2 3 4 2 3 1 4 4 3 2 2 1 2 4 3 1 4 4 1 2

2. **Count the Occurrences of '4'**: Go through the sequence and count how many times '4' appears.
- The sequence contains the following occurrences of '4':
- 1st occurrence: 1 2 3 **4**
- 2nd occurrence: 1 **4**
- 3rd occurrence: **4**
- 4th occurrence: 1 **4**
- Total occurrences of '4': 5 times.

3. **Conclusion**: The student will have to sit down a total of 5 times.

### Final Answer:
The student will sit down **5 times**.