The proof for answer choice (C) can be found throughout the entire passage of course, as this is a Global Organization question, but a few main lines in the beginning of the passage provide strong evidence on their own.
In the beginning of the passage, we are introduced to the idea of scientific disciplines relating to one another as "an antithesis to its thesis" (lines 2-3). Then, in the second paragraph, the author writes that "the relationship of cytology (cell biology) to biochemistry.... exemplifies such a pattern." (lines 14-17). This organization is paralleled perfectly by the organization described in (C), in which a proposition (the relation of disciplines to one another) is stated, and then an example (cytology/biochemistry) is given!
Answer choice (B), while tempting, isn't quite correct. The example of cell biology and biochemistry is not being used to prove that the interaction between disciplines can have important results, rather, the author asserts the additional claim at the end regarding the results and then uses biology and biochemistry as an example (lines 55-64). Basically, the author isn't concluding anything because
of biochemistry and cell biology, instead, they're using biochemistry and cell biology to exemplify the statements they make! It also may be useful to consider how there is not a "set of examples" being provided in the passage, as only one example is discussed. This is further reason to eliminate (B)!
In general, when you're approaching these questions you should already be equipped with your VIEWSTAMP analysis -- rely on it! Throughout your initial reading of the passage, make sure you're actively considering the underlying logical structure and the order in which it is presented. Make sure to remember that you should hold the structure in your mind (as opposed to writing it down) throughout the passage and afterwards.
If you're continuing to struggle, it may be useful to liken these questions to Method of Argument questions on the Logical Reasoning section. In these questions, you're identifying the abstract relationship between the components of the stimulus in a very similar way to identifying the structure and organization of a passage! Keep it up -- the more you practice and familiarize yourself with the structure of Reading Comprehension passages, the easier these questions will become!
I hope this helps