Which is a potential negative consequence of using genetically engineered medicine?

A.Gene markers that are resistant to antibiotics are used, providing the possibility for humans to have increased antibiotic resistance.

B.Products that are used to genetically engineer medicine are poisonous.

C.Restriction enzymes are used to create the medicine and have been known to cause cancer.

D.Medicine that is created this way is less effective than medicine that is created the traditional way.