Correct Option (b):
Ganesh Vasudev Mavalankar was elected as the first Speaker of the Lok Sabha in 1952. He served in this capacity until his demise in 1956. Prior to this, he held the position of Speaker of the Constituent Assembly (Legislative).
Incorrect Options:
Hukum Singh served as the Speaker of the Lok Sabha from 1962 to 1967, making him a subsequent incumbent, not the first.
K. M. Munshi was a distinguished freedom fighter, lawyer, and educationist. He did not serve as a Speaker of the Lok Sabha.
U.N. Dhebar was notably the President of the Indian National Congress during the 1950s. He was not a Speaker of the Lok Sabha.