Çözüldü Sentence Structure - Subject and Verb Agreement - Grammar

In 1822 a revolutionary, multi-prismatic lens designed by Jean Augustine Fresnel, ________ actually a series of concentric rings of segmental lenses, instead of reflecting the light, refracted it.

A) that are
B) is that
C) are which
D) are
E) which is

Correct Choice: E (which is)
Explanation: The subject is "a revolutionary, multi-prismatic lens" and singular, so it takes a singular adjective clause.

Adapted from "Kaplan GRE Premier Program 2009 Ed.", page 76