Step 1: Understanding the foundation of major political organizations.
The Hindu Mahasabha was founded in 1915 by Lala Lajpat Rai and others as a response to the need for a political platform for Hindus during the Indian independence movement.
Step 2: Analyzing the options.
(A) Indian National Congress: The Indian National Congress was founded in 1885, not in 1915.
(B) Hindu Mahasabha: Correct. The Hindu Mahasabha was founded in 1915.
(C) Muslim League: The All India Muslim League was founded in 1906, not in 1915.
(D) Swaraj Party: The Swaraj Party was founded in 1923, not in 1915.
Step 3: Conclusion.
The correct answer is (B) Hindu Mahasabha, as it was founded in 1915.