The correct options are
A Frequency polygon is graphical representation of discrete frequency distribution.
B Frequency polygon is graphical representation of continuous frequency distribution.
A frequency polygon is the graphical representation of both discrete and continuous frequency distribution.
But class marks are first calculated, then they are taken on the X-axis and the corresponding frequency on the Y-axis in constructing the frequency polygon.
Alwyas there is no need for constructing the histogram, the frequency polygon can be made without using the histogram.