64Roger Penrose

[real2008]

The work of mathematician Roger Penrose in the early 1970s, on the geometry of what are called aperiodic tiles, turned out to describe the architecture of a previously unknown class of crystals.
(A) what are called aperiodic tiles, turned out to describe
(B) what is called aperiodic tiles, describes
(C) aperiodic tiles, describing
(D) so-called aperiodic tiles, describe
(E) aperiodic tiles, it turned out to describe

Why not B?

[goelmohit2002]

Probably because tile"s" is plural....

IMO if we do not know whether the thing is singular or plural...then better to go with the case given in the question itself....

[gmat740]

https://www.beatthegmat.com/roger-penros ... tml#162353

please take out little time to search the question, that will save your precious time(especially if you are heading for your GMAT soon!)

[real2008]

any further opinion please? OA is A

[gmat_dest]

Well, the choices are between A and B.

In B, "what is called X tiles" is wrong. "The work...describes" is correct.

A is correct in terms of grammar and also preserves the meaning.