Which scientist is credited with discovering the insecticide DDT and was later awarded the Nobel Prize in Physiology or Medicine for this work?

Introduction / Context:
This question checks knowledge of important discoveries in chemistry and medicine, focusing on the insecticide DDT. DDT played a major role in controlling insect borne diseases like malaria, especially in the mid twentieth century. Although later concerns about environmental damage led to restrictions on its use, the original discovery was considered a major scientific achievement, and the scientist who discovered its insecticidal properties received a Nobel Prize. Remembering this name is a standard requirement in general science sections.

Given Data / Assumptions:

• The substance in question is DDT, a synthetic insecticide.
• The options list Paul Muller, John Dalton, Rudolf and None of these.
• The question explicitly mentions that the discoverer received the Nobel Prize for this work.
• The candidate has to select the name that matches this historical fact.

Concept / Approach:
DDT stands for dichloro diphenyl trichloroethane. Although it was synthesised earlier, its powerful insecticidal properties were discovered and systematically studied by a Swiss chemist, Paul Hermann Muller. For this contribution to the control of insect borne diseases, he received the Nobel Prize in Physiology or Medicine in 1948. John Dalton is known for the atomic theory and work on gases. The option Rudolf is incomplete and does not point to a full famous name associated with DDT. Therefore the correct choice is Paul Muller.

Step-by-Step Solution:
Step 1: Recall that DDT became world famous as a powerful insecticide used widely during and after the Second World War. Step 2: Remember that the scientist associated with recognising its potential and developing it as an insecticide was Paul Hermann Muller, a Swiss chemist. Step 3: Note that Muller received the Nobel Prize in Physiology or Medicine in 1948 for this discovery because of its impact on controlling diseases like malaria and typhus. Step 4: Compare this fact with the options in the question. Step 5: Option A lists Paul Muller, which matches the known scientist. Step 6: Conclude that Paul Muller is the correct answer.

Verification / Alternative check:
An alternative check is to remember other famous contributions. John Dalton is strongly associated with the atomic theory and colour blindness, not with insecticides. The name Rudolf without a surname does not match any widely known Nobel laureate in this area. Since the question hints at a Nobel Prize and DDT specifically, looking for a chemist whose research directly affected public health leads back to Paul Muller. This confirms the choice.

Why Other Options Are Wrong:
John Dalton lived in the nineteenth century and contributed to early atomic theory, long before DDT became prominent in the twentieth century. The option labelled Rudolf is incomplete and does not correspond to a famous DDT researcher and does not match the Nobel Prize record. None of these would be wrong because there is a correct name among the options, namely Paul Muller. Therefore, all other options fail to match the combined conditions of DDT discovery and Nobel Prize recognition.

Common Pitfalls:
Learners sometimes confuse the synthesising of a chemical with discovering a particular application such as insecticidal action. Another error is to assume that any chemist who is famous must have been involved in many discoveries and to guess randomly among names. To avoid such mistakes, it helps to connect DDT specifically with a story of disease control and the Nobel Prize in Physiology or Medicine in 1948, which clearly points to Paul Hermann Muller rather than to physicists or earlier chemists.

Final Answer:
The scientist who discovered the insecticidal properties of DDT and received a Nobel Prize for this work is Paul Muller.