What was revolutionary about Galileo's discoveries with his self-designed telescope?
A) He observed the phases of Venus, which supported the heliocentric model of the solar system.
B) He discovered the four largest moons of Jupiter, providing evidence for celestial bodies orbiting something other than Earth.
C) He observed the craters and mountains on the Moon, challenging the notion of a perfect celestial sphere.
D) He observed the phases of Saturn, revealing that it had rings, which contradicted the prevailing belief of a perfect, unchanging cosmos.
E) All of the above.
