The author starts off with a description of a general concept of how one scientific discipline relates to another during its early stages of development, i.e. thesis vs. antithesis. The author proceeds with providing a specific example of this pattern, using the relationship of cytology to biochemistry. The contrasting views of these two disciplines gradually evolved and eventually resulted in a synthesis in the form of molecular genetics. The author concludes that this competition between paired disciplines is important and is a source of scientific progress.
Since a specific example is central to this passage, we can eliminate all the answer choices that fail to include an example - (A), (E), (D). (B) talks about a set of examples, whereas the author only discusses one example of biochemistry and cytology, thus (B) is also incorrect. (C) is the most accurate description of the organization of the material in the passage - a general proposition is provided, and then an example is given, followed by a conclusion.
Let me know if this makes sense and if you have any further questions.
