The newly found drug on the epidemic was not at all deleterious.

The correct answer is A. effective.

The word “deleterious” means harmful or destructive. In the context of the question, the newly found drug was not harmful or destructive to the epidemic. In fact, it was effective in treating the epidemic.

The other options are incorrect because they do not accurately describe the newly found drug. Option B, intoxicating, means causing intoxication or drunkenness. Option C, noxious, means harmful or poisonous. Option D,

In conclusion, the correct answer to the question is A. effective. The newly found drug was not at all deleterious, meaning it was not harmful or destructive. In fact, it was effective in treating the epidemic.