Step 1: Understanding Sensex.
The Sensex is an index that tracks the performance of 30 major companies listed on the Bombay Stock Exchange (BSE).
Step 2: Analyzing the options.
(A) 30: Correct. The Sensex is based on the performance of 30 major companies listed on the BSE.
(B) 50: Incorrect. The Sensex includes only 30 companies, not 50.
(C) 75: Incorrect. The Sensex consists of only 30 companies.
(D) 100: Incorrect. The Sensex includes 30 companies, not 100.
Step 3: Conclusion.
The correct answer is (A) 30, as the Sensex tracks the performance of 30 major companies listed on the BSE.