Final answer:
The correct answer according to the one-year calendar model based on the Big Bang theory is c.) Life appears on Earth. This model condenses the universe's history since the Big Bang into a single year, where life emerges in September.
Step-by-step explanation:
The correct answer to the question is c.) Life appears on Earth:
The one-year calendar model of the universe's history condenses the approximately 13.8 billion years since the Big Bang into a single calendar year to help visualize astronomical time scales. In this model, the Big Bang occurs at the very beginning of January 1st. The formation of the solar system, including Earth, is represented by late August or early September. By this calendar, life appears on Earth somewhere in September, representing the point in time when simple life forms began to emerge.
Homo sapiens, modern humans, don't appear until late December in this model, comprising just the last moments of the cosmic calendar year. This shows just how recent human existence is in the grand scheme of the universe's history. The calendar analogy is a useful tool in understanding these vast timescales and the progression of events in the evolution of the universe.