Answer:
C. Elizabeth wants to estimate the mean vacation days of coworkers at her company. She collects data by selecting a random group of coworkers within her department.
Step-by-step explanation:
Sampling Bias is case, in which some section of population have higher or lower chance of being selected in sample than others.
'Elizabeth wants to estimate the mean vacation days of coworkers at her company. She collects data by selecting a random group of coworkers within her department'. This case is of Convenience Sampling, where person selects sample only as per his/ her convenience.
Elizabeth has conveniently chosen sample workers from her department, so they have higher chance of being in sample, others have lesser chance. Hence, this is Sampling Bias
