This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Biostats, Subject name: Social & Preventive Medicine
All are true except 
Select and explain. 
A. Frequency distributions are usually illustrated by histograms, B. Frequencies are commonly illustrated by bar cha in qualitative data, C. Line cha is useful when comparing two or more frequency distributions by drawing them on the same diagram, D. Bimodal frequency distribution has two tails and one peak
D: Bimodal frequency distribution has two tails and one peak
Answer: D: Bimodal frequency distribution has two tails and one peak 
Explanation: Bimodal frequency distribution: Bimodal frequency distribution has two tails and two peaks Bar cha: Used with categorical and numerical variables Each bar represent one category Bars should separate Y axis should begin with 0 Each bar represent one category and its high is the frequency or relative frequency Frequency cha: No spaces between bars Quantitative variable X axis should be continuous Y axis should begin with 0 The area bar, not its high, represent its frequency