The correct answer is (a) 6th Sept., 1932.
Nagendra Saklani was a freedom fighter from Uttarakhand, India. He was born on 15th August, 1909 in the village of Saklana, Tehri Garhwal. He was educated at the Government Inter College, Dehradun and the University of Allahabad. He joined the Indian National Congress in 1928 and actively participated in the freedom struggle. He was arrested several times by the British government and was imprisoned for a total of six years. He was martyred on 6th September, 1932 while leading a protest against the British government.
(b) 9th June, 1930 is the date on which Bhagat Singh, Sukhdev Thapar and Rajguru were hanged by the British government.
(c) 11th January, 1948 is the date on which Mahatma Gandhi was assassinated by Nathuram Godse.
(d) 23rd April, 1930 is the date on which the Salt March, also known as the Dandi March, was launched by Mahatma Gandhi.