Given below are four jumbled sentences. Select the option that gives their correct logical sequence. A. These can turn around to track stars with the rotation of Earth. B. Observatories are places to study place. C. They are mostly built on the mountain tops. D. Telescopes are placed in the dome-shaped roof of the building.

Correct — C. Order these on reference, not on subject matter.

Only B has a full noun subject and points back to nothing, so it opens. C follows, because its They can then only mean observatories — mostly built on the mountain tops.

D narrows from the building to what sits inside it: telescopes in the dome-shaped roof. A closes, because its These can only be those telescopes — only a telescope turns to track stars.

BCDA is an unbroken chain of reference — option (c).

Why the others are wrong

• (a)
  DCBA — DCBA opens on the dome-shaped roof of the building before any building has been mentioned, and its They in C would then claim telescopes are built on mountain tops.
• (b)
  CBDA — CBDA starts with They, a pronoun with nothing in front of it to point at.
• (d)
  ACDB — ACDB starts with These, the same fault, and pushes the defining sentence B to the very end — after everything it was meant to set up.

A four-sentence jumble is decided on pronoun reference.

Scan for the sentence that introduces a noun and contains no pronoun and no connector: that is the opener.

Then follow each pronoun to the nearest antecedent that makes sense — They needs a plural noun already named, These needs one named closer still and doing what its sentence describes.

The order settles itself once every pronoun has something earlier to point at, and the paragraph then runs general to specific: what observatories are, where they stand, what they hold, what that instrument does.

Key facts

• A sentence opening with They, These, It or Such can almost never open a jumbled paragraph.
• These in sentence A must follow sentence D: of the nouns available, only telescopes turn to track stars.
• Descriptive paragraphs of this kind run definition, then location, then contents, then function.

Common traps

• Ordering by what feels like the main topic, starting with telescopes, instead of by reference
• Overlooking that They and These point to different nouns in this set
• Treating B's odd wording as a reason to demote it from the opening position

No directly related past PYQ was found.