What does it mean to calculate frequencies within a dataset?

to count the number of times a dataset is used by a student

to calculate the product of two variables to make a third variable

to count the number of cases that fall into different subgroups within a dataset

to calculate the sum of a column of variables in a dataset

to count the number of cases that fall into different subgroups within a dataset.

Explanation:

To calculate the frequency within the dataset means to count the number of times that item or condition on which we are checking the column within the dataset is true or the frequency of the case that is coming into different subgroups.

Hence the answer of this question is third option given in the question.