(A) during sleep in higher concentrations than when awake
(B) when sleeping in higher concentrations than waking hours
(C) in higher concentrations during sleeping than waking
(D) in higher concentrations during sleep than during waking hours
(E) in higher concentrations when asleep than when awake
Solution:
Modifiers + Parallelism
In A and B, “higher concentrations” is modifying incorrectly “sleep” instead of “secreted”.
In C, “sleeping” and “waking” are adjectives that have been used instead of nouns such as “waking hours”.
E suggests that when the “gland” is “asleep” higher concentration of hormone is secreted.
In D, both “sleep” and “waking hours” are nouns and hence, D maintains parallelism and is logical. D is the best choice.
Sentence Correction - 1000 Questions with Solution:
