How will the right answer fit in terms of support and conclusion?

Only the right answer will be a conclusion guaranteed by support in the passage.

Highlight the main conclusion in the passage, if there is one:

There is no conclusion in the passage. The right answer will be the conclusion.

[SUPPORT]. Furthermore, [SUPPORT].

Map the wording of the answers to the wording of the passage:

(A) Beliefs for which a person does not have observable evidence…

…are never mentioned in the passage. You can’t make a conclusion about something that never gets mentioned.

(B) Beliefs based on information from a reliable sources are self-evident.

This directly contradicts the second sentence of the passage.

(C) All reasonable beliefs for which a person has no observable evidence…

Stop. The passage only says that beliefs like this exist, but doesn’t say anything about them at all, let alone about all of them.

(D) …then it is not self-evident either.

Just because the passage said that “some beliefs” are “neither self-evident nor grounded…” doesn’t mean that any belief that’s one of these things is also the other.

(E) …there are some beliefs that are not grounded in observable evidence.

This is a really dumb way of saying the same thing the second sentence says. Before you waste your youth trying to deeply understand all those details, let’s agree that this is the only answer that doesn’t contradict the passage, bring in something new, or use stronger wording than the passage uses. That’s probably easier to recognize, but it proves this is the right answer all the same.

That said, let’s sub in easier details to match the second sentence to this answer. Let’s say ‘there are some days that are neither rainy nor cold.’ To put that in the form of this answer, we’d say ‘among days that are not rainy, there are some that are not cold.’ Yup, those mean the same thing, so it’s reasonable that one “must be true” based on the other.

(E) is the correct answer.