Final answer:
An organism with tissues that contained no cells would be the piece of evidence most likely to lead to a revision of cell theory, as it would challenge the fundamental tenet that all living organisms are composed of cells.
Step-by-step explanation:
The evidence that would most likely cause scientists to revise the cell theory would be if an organism was found with tissues that contained no cells (Option A). This finding would directly contradict the central tenet of the cell theory that all living things are made up of cells, which is considered the structural unit of living organisms. Additionally, cell theory asserts that new cells arise from existing cells. Finding an organism without cellular structure would challenge these fundamental concepts and necessitate a revision of the theory.
While finding a cell that can divide endlessly (Option B) or an animal cell that can harness solar energy (Option C) would be significant discoveries, they wouldn't contradict the core principles of cell theory. Likewise, discovering cells that use something other than DNA (Option D) would be a groundbreaking discovery, but it would not challenge the view that cells are the basis of all life forms; only the mechanism of heredity would be called into question.