Given a text T, and several options, according to the question posed in the text T to choose the most appropriate option from the options as the answer, please directly output the most appropriate option, do not need to output the explanation.

A heat map is best suited for visualizing the:
Option A:frequency of textual data.
Option B:degree of correlation between different variables.
Option C:shape, center, and spread of the distribution of numerical data.

Answer: B