Nearly all employees of the factory who have completed their high school diploma have earned their factory safety certificate, having easily completed the eight week training course. The high school graduates who haven't earned the certificate are ones who have evening obligations that have prevented them from taking the course. Overall, though, most of the factory workers have not earned the certificate.

If the statements above are true, which one of the following also must be true?

A:A large proportion of students with high school diplomas have evening obligations that have prevented them from taking the eight week training course.

B:No factory worker without a high school diploma has completed the course and earned the certificate.

C:Most of the workers who have earned the certificate are high school graduates.

D:A large proportion of the factory workers have not graduated from high school.

E:Most of the people who take the training course are able to earn the safety certificate.