1. Every scientific theory starts with an observation of an unexplained phenomenon. Scientists look to explain such phenomena by developing theories. The first step is to develop a hypothesis, which can be a suggested solution for the unexplained occurrence (phenomenon). After substantial research and experimentation, and if enough evidence accumulates to support a hypothesis, it is widely accepted as the best possible explanation. This hypothesis has now moved on the next step — and it is on its way to becoming a theory — in the scientific method. This theory becomes accepted as a valid explanation of a phenomenon. One of these theories is the Cell Theory. SC.912. L.14.1 . Which is not a part of the Cell Theory? (1 Point) A. All living organisms are composed of cells. B. The cell is the basic unit of life. C. Cells arise from pre-existing cells. D. Cells, the basic unit of life, are derived from spontaneous generation.