Step 1: Understanding the Question
This question asks to identify the founder of the newspaper named 'Mooknayak'.
Step 2: Recalling Historical Facts
'Mooknayak', which translates to "Leader of the Dumb" or "Leader of the Voiceless," was a Marathi fortnightly newspaper.
It was started by Dr. B. R. Ambedkar on January 31, 1920.
The newspaper's purpose was to champion the rights and causes of the depressed classes (Dalits) in India.
Step 3: Evaluating the Options
(A) Mahatma Gandhi: He started several journals, including 'Harijan', 'Young India', and 'Navjivan'.
(B) Dr BR Ambedkar: He is the founder of 'Mooknayak'. He also started other periodicals like 'Bahishkrut Bharat'.
(C) Nethaji Subhash Chandrabose: He was associated with newspapers like 'Forward Bloc'.
(D) Pandit Jawaharlal Nehru: He started the newspaper 'National Herald'.
Step 4: Final Answer
Dr. B. R. Ambedkar started the newspaper 'Mooknayak'. Therefore, option (B) is the correct answer.