To Determine Attack Rates for a Respiratory Disease of Unknown

To determine attack rates for a respiratory disease of unknown origin among people attending a conference, random samples of guests staying at four hotels were
Surveyed for subsequent illness.Because it was not feasible to survey all guests,
Random sampling provided the best information because:

A) It would identify all cases of disease
B) It would avoid selection bias
C) It would reduce measurement bias
D) It would eliminate sampling error
E) It would eliminate confounding