Final answer:
The Oscillating Universe Theory represents the concept of a cyclical universe, with successive periods of expansion and contraction. This theory has been challenged by the discovery of dark energy, which suggests that the universe's expansion is not slowing down. The Big Bang Theory, supported by the CMB evidence, is the prevailing model of the universe's origin and expansion.
Step-by-step explanation:
The theory represented by an oscillating universe is c) Oscillating Universe Theory. This concept is built on the idea that the universe undergoes a cycle of expansions and contractions. It speculates that after a Big Crunch, which is a hypothetical collapse of the universe upon itself after a period of expansion, a new Big Bang could occur, leading to another expansion phase, and this process might repeat indefinitely.
However, this theory has been challenged by the discovery of dark energy, which suggests that the universe's expansion is accelerating rather than slowing down, making a Big Crunch and subsequent oscillating universe seem less likely.
Despite the appeal of the Oscillating Universe Theory, the Big Bang Theory remains the predominant cosmological model, supported by evidence such as the cosmic microwave background radiation (CMB), and it does not inherently include an oscillation between expansion and contraction.