For the discovery of which antibiotic drug did Selman Waksman receive the Nobel Prize in Physiology or Medicine?

Introduction / Context:
The development of antibiotics transformed modern medicine by making it possible to treat many bacterial infections effectively. Several scientists were honoured with Nobel Prizes for their work in this field. Selman Waksman, a microbiologist, is associated with the discovery of a specific antibiotic that proved effective against tuberculosis.

Given Data / Assumptions:

• The scientist named is Selman Waksman.
• The award mentioned is the Nobel Prize in Physiology or Medicine.
• The options list several antibiotic names.

Concept / Approach:
Waksman and his team isolated streptomycin from soil microorganisms. Streptomycin was the first antibiotic found to be highly effective against Mycobacterium tuberculosis, the bacterium that causes tuberculosis. Penicillin, on the other hand, was discovered by Alexander Fleming and later developed by others, so it cannot be linked to Waksman's Nobel Prize.

Step-by-Step Solution:
Step 1: Recall that Waksman worked on antibiotics derived from soil actinomycetes.Step 2: Identify streptomycin as his most famous discovery, especially in relation to tuberculosis treatment.Step 3: Review the other options and connect them with different scientists or later drug developments.Step 4: Choose streptomycin as the correct answer.

Verification / Alternative check:
A cross check is to link each antibiotic with its key discoverer. Penicillin is linked with Fleming, chloromycetin with broad spectrum use but not Waksman, and neomycin with later research but not Nobel recognition at that time. Streptomycin appears repeatedly in discussions of Waksman's work and the Nobel citation, confirming that it is the right choice.

Why Other Options Are Wrong:
Penicillin is very important but it was not Waksman's discovery; its recognition went to other scientists. Chloromycetin and neomycin are important antibiotics but are not the specific reason for his Nobel award. Ampicillin is a later semi synthetic penicillin and is therefore unrelated to Waksman's classic work with soil microbes.

Common Pitfalls:
Many candidates instinctively pick penicillin whenever they see a question about antibiotic discovery because it is the most famous example. Others may confuse streptomycin with a different drug used for tuberculosis. Carefully linking each key scientist with one signature antibiotic helps avoid such errors; in this case the pair is Waksman and streptomycin.

Final Answer:
The correct answer is Streptomycin.