Hi, we need to figure out what the author believes about scientific truth. We know from the second paragraph that the author rejects the earlier views of the historians, the author clearly thinks that there is such a thing as objective scientific truth.
This gives us a strong reason to think the author doubts that all scientific ideas are subject to inevitable falsification. In fact, the author seems to clearly tell us in the second paragraph that certain ideas, like the composition of water, are not going to be disproven.
However, the third paragraph gives us clear support for C. Around lines 35 to 40, the author tells us clearly that scientific discovery is a complex and difficult process, which tends to support the idea that the author thinks discovery is not obvious or transparent.