Professional American football player Fred Cox invented one of the world’s most popular toys. In the 1970s, he came up with
the idea for the Nerf football, which ______ of the harder and heavier regulation football.
were a smaller, foam version
are smaller, foam versions
were smaller, foam versions
is a smaller, foam version
Choice D is the best answer. The convention being tested is subject-verb agreement and agreement between nouns. The
singular verb “is” and the singular noun “version” both agree in number with the relative pronoun “which.” In this context,
“which” functions as a singular subject because it refers to the singular noun “the Nerf football.”
Choice A is incorrect because the plural verb “were” doesn’t agree in number with the singular noun phrase “the Nerf
football” that it’s modifying. Choice B is incorrect because the plural verb “are” and the plural noun “versions” don’t agree in
number with the singular noun phrase “the Nerf football” that they’re modifying. Choice C is incorrect because the plural verb
“were” and the plural noun “versions” don’t agree in number with the singular noun phrase “the Nerf football” that they’re
modifying.