Which choice completes the text so that it conforms to the conventions of Standard English?
A
Those
B
They
C
It
D
Some
Explanation
Correct answer: C.
Choice C is the best answer. The convention being tested is pronoun-antecedent agreement. The singular pronoun "it" agrees in number with the singular antecedent "multitask learning" and clearly indicates what multitask learning involves.
Why the other choices are wrong
Choice A
Choice A is incorrect because the plural demonstrative pronoun "those" doesn’t agree in number with the singular antecedent "multitask learning."
Choice B
Choice B is incorrect because the plural pronoun "they" doesn’t agree in number with the singular antecedent "multitask learning."
Choice D
Choice D is incorrect because the indefinite pronoun "some" is ambiguous in this context; the resulting sentence leaves unclear what exactly "involves training computer models."