I think option A is the correct answer.
The argument starts with a specific situation:
“theories in certain scientific fields may be in flux today”
Then it explains that this situation is actually part of a broader pattern:
whenever many new facts are discovered,
the field naturally needs to reorganize its knowledge.
So the author takes one situation
(scientific theories being unsettled today)
and explains it through a general rule or pattern.
That is exactly what option A says.
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Why the other options are wrong:
(B)
The argument never talks about bad consequences
of accepting another explanation.
So this is irrelevant.
(C)
The argument does not say two explanations
are equally probable.
In fact, it clearly prefers one explanation:
scientific progress.
(D)
The passage is not citing a “law of nature.”
It is just describing a general tendency
in scientific fields.
(E)
There is no discussion of intended outcomes
or planned actions.
The argument only explains why the situation exists.
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So the structure is:
specific situation
→ explained using a broader general pattern
Answer = A
— Rajdeep