Question

at a nutrition conference organized by the global health alliance in 2018, scientists presented groundbreaking results. data showed that participants who followed a structured plant - based diet saw improvements in cardiovascular health significantly sooner than expected. they also demonstrated lower cholesterol levels over the following year than
19
mark for review
which choice completes the text so that it conforms to the conventions of standard english?
a that of those who maintained a conventional mixed diet.
b that of those, who maintained a conventional mixed diet.
c those who maintained a conventional mixed diet.
d those, who maintained a conventional mixed diet.

Explanation:

To solve this, we analyze the comparison. The sentence compares cholesterol levels of two groups: those on a plant - based diet and those on a conventional mixed diet. The pronoun "that" is used to refer to a singular noun (here, "cholesterol levels" is a singular concept in terms of the measurement, so "that" is appropriate to refer to "cholesterol levels"). Also, the non - restrictive clause here is incorrect as we need a restrictive clause to define "those" (the group with the conventional mixed diet). Option A uses "that" to refer to "cholesterol levels" and has the correct restrictive clause (no unnecessary comma before "who"). Option B has an incorrect comma before "who" (making it a non - restrictive clause incorrectly). Option C uses "those" which would be incorrect as "cholesterol levels" is a singular concept in this comparison context. Option D has an incorrect comma and incorrect pronoun ("those" instead of "that").

Answer:

A. that of those who maintained a conventional mixed diet.