The development of cell theory was not without argument. The theory of spontaneous generation states that life arose from nonliving matter. and this was a long-held belief dating back to Aristotle and the ancient Greeks. Starting in 1668 with the experiments of Francesco Redi, scientists tried to refute this theory. It was not until the second half of the 1800's that Pasteur's experiments irrefutably disproved the theory of spontaneous generation. This lead to which point in cell theory?

A) DNA is passed from cell to cell.
B) Energy flow occurs within cells.
C) Cells arise from pre-existing cells.
D) All living things are composed of one or more cells.