Explanation:

- Preeti is the thirteenth girl from the left side of the row.

- Molly is third to the right of Preeti.

- This means Molly's position from the left is 13 + 3 = 16.

- Molly is also stated to be the twenty-third from the right.

- To find the total number of girls, add Molly's position from the left and right and subtract 1, because her position is counted twice:

- Total girls = 16 (from left) + 23 (from right) - 1 = 38.

- Option 1: 32 - Incorrect, as it does not match our calculation.

- Option 2: 31 - Incorrect, as it does not match our calculation.

- Option 3: 34 - Incorrect, as it does not match our calculation.

- Option 4: 38 - Correct, matches our calculation.