**Core Concept**
The Dentist Act of 1948 is a landmark legislation that regulates the dental profession in India, ensuring the provision of safe and quality dental care to the public. This act is a crucial aspect of dental law and ethics, governing the practice of dentistry in the country.

**Why the Correct Answer is Right**
The correct answer is B. 29th March 1948, as this is the date when the Dentist Act was introduced. This act aimed to establish a comprehensive framework for the registration, education, and practice of dentists in India. The act mandated the establishment of the Dental Council of India (DCI), which is responsible for overseeing dental education and ensuring that dental professionals meet the required standards of competence and ethics.

**Why Each Wrong Option is Incorrect**
**Option A:** 27th March 1948 is incorrect as it is a day before the actual date of introduction of the Dentist Act.

**Option C:** 27th March 1949 is incorrect as it is a year after the actual date of introduction of the Dentist Act.

**Option D:** 29th March 1949 is incorrect as it is a year after the actual date of introduction of the Dentist Act.

**Clinical Pearl / High-Yield Fact**
The Dentist Act of 1948 is a significant milestone in the history of dentistry in India, marking a shift towards a more structured and regulated approach to dental education and practice.

**✓ Correct Answer: B. 29th March 1948**