A relative frequency histogram having classes of greatly different class widths was used as an estimator of a continuous population pdf. The relative frequency was plotted versus the class intervals. This plot will not be an appropriate estimator of the population pdf because
A. all the intervals are not the same width.
B. the area under the curve for each class is not an estimator of the probability of that class.
C. the area under the curve is not proportional to one.
D. the relative frequency varies greatly by class width.
E. In fact it is an unbiased estimator of the pdf.