Do Doctors in Managed Care Plans Give Less Charity Care

Do doctors in managed care plans give less charity care? Researchers chose 60 communities at random, then chose doctors at random in each community. In all, they interviewed 10,881 doctors. Overall, 77.3% of the doctors said they had given some care free or at reduced rates because of the patient's financial need in the month before the interview. Doctors who received at least 85% of their practice income from managed care plans were significantly less likely than other doctors to provide charity care.
The phrase "significantly less likely" means that, when we compare the charity work of doctors with more than 85% of their practice in managed care with other doctors,

A) the difference in charity work is very large.
B) the difference in charity work is so large that it would rarely occur just by chance in choosing a sample.
C) the difference in charity work is large enough to affect doctors' incomes.
D) the difference in charity work is less than we would expect just by chance in choosing a sample.