Explanation: The words <em>minimal</em> and <em>copious</em> are antonyms (<em>copious</em> means "abundant" and the meaning of <em>minimal</em> is transparent); therefore, we have to choose a word opposite in meaning to <em>disgruntled</em> (angry, implying dissatisfaction): that word is <em>contented, </em>which is a synonym of <em>satisfied</em>.
For the main reason that "it promoted sacrifice for the common good." the speech was commonly read during the Cultural Revolution. This speech was the primary political propaganda of Mao Zedong as a slogan during the dark times of the Chinese cultural history.
