Explanation:

To find the lower limit of the first class interval, we need to determine the smallest value in the given data set.

Given class marks distribution: 25, 26, 27, 31, 36, 41, 46, 51, 57, 59

Step 1: Sort the data in ascending order.
25, 26, 27, 31, 36, 41, 46, 51, 57, 59

Step 2: Identify the smallest value in the data set.
The smallest value in the data set is 25.

Step 3: Define the class intervals.
Since the question does not provide the width of the class intervals, we cannot determine the exact class intervals. However, we can infer that the class intervals are of equal width since the data set is presented in a tabular form.

Step 4: Determine the lower limit of the first class interval.
To find the lower limit of the first class interval, we subtract half of the class interval width from the smallest value in the data set.

In this case, since we do not know the exact class interval width, we cannot calculate the exact lower limit of the first class interval. However, we can approximate the lower limit based on the given answer options.

The options provided are:
a) 40
b) 42
c) 23.5
d) 24.5

Step 5: Analyze the answer options.
Given that the lowest value in the data set is 25, options a) and b) can be eliminated since they are greater than 25. Therefore, the lower limit of the first class interval must be less than 25.

Option c) 23.5 is also incorrect because it is less than the smallest value in the data set.

Therefore, the correct option is d) 24.5, which is slightly less than the smallest value in the data set.

Conclusion:
The lower limit of the first class interval is 24.5.