Who among the following was the personal physician of the Kushana ruler Kanishka and is also regarded as the author or redactor of a famous treatise on the Indian system of medicine?

Introduction / Context:
This question concerns the history of ancient Indian medicine (Ayurveda) and its connection with the Kushana emperor Kanishka. Some of the most famous names in classical Indian medical literature are Charaka and Susruta. The question asks which physician was associated personally with Kanishka and also linked with an important medical treatise, making it a test of both dynastic and scientific history.

Given Data / Assumptions:

• Kanishka was a prominent Kushana ruler.
• He had a personal physician associated with his court.
• The physician in question is connected with a famous medical treatise.
• The options include Charaka, Susruta, Nagarjuna and Jevaka, all connected with Indian science or medicine in different ways.

Concept / Approach:
The core concept is the association of Charaka with both Kanishka and the Charaka Samhita. Tradition holds that Charaka served as a court physician to Kanishka and contributed to the compilation or redaction of the Charaka Samhita, one of the foundational texts of Ayurveda. Susruta is associated with the Susruta Samhita and with surgery, but not specifically with Kanishka. Nagarjuna is known for Buddhist philosophy and alchemy, and Jevaka is traditionally associated with the Buddha, not with Kanishka. Therefore, Charaka best fits all parts of the description.

Step-by-Step Solution:
Step 1: Identify the ruler mentioned: Kanishka, a well known Kushana emperor. Step 2: Recall that Charaka is a classical Ayurvedic authority linked to the text Charaka Samhita. Step 3: Traditional accounts mention Charaka as a physician at the court of Kanishka, aligning him with the dynasty mentioned. Step 4: Cross check that Susruta, though a great surgeon, is not usually connected with Kanishka's personal court in standard narratives. Step 5: Therefore, the correct answer is Charaka.

Verification / Alternative check:
Histories of Indian medicine typically mention that the Charaka Samhita is one of the earliest and most authoritative texts of Ayurveda and that Charaka is linked by tradition to the Kushana court of Kanishka. Susruta, by contrast, is associated with surgical techniques and another major text, the Susruta Samhita. Jevaka is remembered as the physician of the Buddha, and Nagarjuna is better known as a Buddhist philosopher and alchemist. These distinctions verify Charaka as the correct choice.

Why Other Options Are Wrong:
Susruta: A legendary surgeon and author of the Susruta Samhita, but not commonly identified as Kanishka's personal physician.
Nagarjuna: Famous as a Buddhist philosopher and sometimes as an alchemist, with no strong traditional claim of being Kanishka's court physician and the author of an Ayurvedic samhita in this sense.
Jevaka: Traditionally regarded as the personal physician to Gautama Buddha, not to Kanishka, and associated with an earlier period.

Common Pitfalls:
A common error is to confuse Charaka and Susruta because both are central names in Ayurveda. Some students also mix up Jevaka's connection with the Buddha and Kanishka's court due to both being tied to Buddhism. Carefully matching each personality with the correct ruler and text helps keep these figures distinct in memory.

Final Answer:
The personal physician of Kanishka and author redactor of a famous medical treatise was Charaka.