A Statistics Class Has 50% Females and 50% Males

A statistics class has 50% females and 50% males.A researcher randomly selects a sample that has 80% males and 20% females.Why should the researcher be cautious of making inferences about the entire class based on the sample?

A) Because,by luck of the draw,the sample is unrepresentative of the population.
B) Because,by luck of the draw,the sample is representative of the population.
C) Because,by luck of the draw,the opinions of the females in the sample will not be the same as those of the females in the population.
D) Because,by luck of the draw,the sample was too small.