The correct answer is: A. Mahatma Gandhi
Mahatma Gandhi was the first person to call Subhash Chandra Bose as ‘Desh Nayak’. He did so in a letter to Bose in 1938. In the letter, Gandhi praised Bose for his patriotism and his commitment to the Indian independence movement. He also expressed his hope that Bose would continue to play a leading role in the movement.
Ram Manohar Lohia was a socialist leader who was also a close associate of Gandhi. He was a strong supporter of Bose and his efforts to achieve Indian independence. However, he never called Bose as ‘Desh Nayak’.
Rabindranath Tagore was a Bengali polymath who was also a strong supporter of Bose. He was a Nobel laureate in literature and is considered to be one of the greatest writers in the history of the Bengali language. However, he never called Bose as ‘Desh Nayak’.
Sardar Vallabhbhai Patel was a freedom fighter and statesman who was one of the most important leaders of the Indian independence movement. He was also the first Deputy Prime Minister of India. However, he never called Bose as ‘Desh Nayak’.
In conclusion, the only person who had called Subhash Chandra Bose as ‘Desh Nayak’ was Mahatma Gandhi.