Final answer:
Mustapha Mond believes that God manifests himself through the societal stability and happiness achieved by scientific control, rather than through traditional religious means. The answer is option C.
Step-by-step explanation:
According to Mustapha Mond in Aldous Huxley's Brave New World, God does not manifest himself to modern men through traditional means such as ancient scriptures, natural phenomena, or direct revelation. Instead, Mustapha Mond asserts that an evolved society such as theirs has outgrown the need for God, as scientific advances and societal changes have effectively replaced the functions that religion historically served.
In a broader sense, Mond implies that in this future society, God is manifested through the societal stability and happiness achieved by the scientific control of nearly every aspect of human life. This view reflects a post-religious, utilitarian philosophy where scientific discoveries and human ingenuity are deemed the highest authorities.