The Manufacturers of a Popular Diet Drug Claim That the Drug

The manufacturers of a popular diet drug claim that the drug can help reduce food cravings in order to aid in weight loss. But in a recent study, researchers proved that the main ingredient in the drug has no effect on weight loss. If another study proves that the other ingredients, of which there are only three, also have no effect on weight loss, then clearly the drug is not actually effective.
The argument is flawed because it

A) Presumes that a combination must lack a specific quality if each individual part also lacks that quality.
B) Confuses cause with correlation.
C) Relies on an unrepresentative sample to draw broad conclusions.
D) Assumes that a claim must be false if the person behind the claim has a proven bias.
E) Overlooks the possibility that acting as a placebo is a valid use for a drug.