Studies of the human sleep-wake cycle have practical relevance for mat

POE:
A) If we were to plug this into the sentence, it would read "ranging from the staff of shifts". Staff is a noun which means employees. It doesn't make sense to say the staff of shifts in a 24 hour factory. What is the staff doing? This sentence is an incomplete thought.
B) Those has no logical antecedent. Also if it did, it wouldn't fit into the sentence
C) Correct. Exactly what we're looking for. Studies help the staffing of shifts in 24 hour factories. Makes sense
D, E) We need to create a range when we use FROM. From X .... TO Y. If we said FROM X.... AND Y, our range is never closed.

The correct idiom is ranging from X to Y
For this reason, D and E can be eliminated as they use and instead of to.
In B, X is “duty assignments”. If X has a noun then Y must have a noun or a gerund for parallelism. But in B, “staff” is used as a verb so B is also eliminated.
A is also wrong as it is comparing "duty assignments" to "staffs". This is awkward.
In C, parallelism is maintained - “ranging from duty assignments in… to the staffing of…”.
"Staffing" is a gerund and is preceeded by "the" and followed by "of": The conventional way to differentiate a gerund from a present participle.

Correct answer is C.

Studies of the human sleep-wake cycle have practical relevance for matters ranging from duty assignments in nuclear submarines and air-traffic control towers to the staff of shifts in 24-hour factories.

(A) to the staff of

(B) to those who staff

(C) to the staffing of

(D) and staffing

(E) and the staff of

The key is, "from X to Y". Both X and Y have to have parallel structure.
Eliminate (D) and (E)
"duty assignments" is a noun subject
(B) is wrong because it is unclear what the word "those" refers to
(C) appears to be incorrect, but I believe the V+ing act as a verbing noun here

Ans: (C)

Hmm first let's talk about the meaning of sentence, the sentence says that the some studies of the human sleep-wake cycle have found a relevance for different matters ranging from blah blah to blah.

Now in the non-underlined part we have 'ranging FROM', which means we need to have the idiom ranging FROM X TO Y
Also we have two elements which should be parallel in the list (duty assignments and staffing), now again in non underlined part 'duty assignments in nuclear submarines and air traffic control towers' is Noun so we need another noun to fix the parallelism issue.

Studies of the human sleep-wake cycle have practical relevance for matters ranging from duty assignments in nuclear submarines and air-traffic control towers to the staff of shifts in 24-hour factories.

(A) to the staff of ---> Here Staff of changes the meaning we are not talking about the staffs of some work force but the nature of things which affects the human sleep-wake cycle

(B) to those who staff --> What does 'those' refer to here, let's suppose if it referred to something, even then it is wrong since it is a clause with staff as a verb and we need a noun for parallelism

(C) to the staffing of --> Perfect One it follows the idiom From X to Y and also 'the staffing of' is a noun phrase saying it is the duty assignments and the staffing which is affecting the nature of things

(D) and staffing --> Incorrect idiom From X and ?

(E) and the staff of --> same as D

Official Explanation :

The best answer for this question must have a phrase parallel to from duty assignments - that is, a phrase with the preposition to and a word that indicates a thing or an activity.

Choices D and E can be faulted for having and in place of to .

Choices A, B, and C supply the proper preposition, but A and B attempt to parallel duty assignments with staff-that is, with people.

Only choice C combines the proper preposition with the staffing , a correct parallel to duty assignments .

Hello Guys,

Can anyone explain the meaning of the sentence? I didn't get the meaning

Studies of the human sleep-wake cycle have practical relevance for matters ranging from duty assignments in nuclear submarines and air-traffic control towers to the staff of shifts in 24-hour factories.

(A) to the staff of - parallelism issue - the staff is not logically parallel to duty assignments

(B) to those who staff - parallelism issue - 'those who staff' is not logically parallel to duty assignments

(C) to the staffing of - Correct

(D) and staffing - Idiom issue - from X to Y is the correct idiom

(E) and the staff of -- Idiom issue - from X to Y is the correct idiom

Answer C

staff and staffing both are noun ......
staff=worker
staffing=the decisions and activities connected with providing staff for an organization

Hi GMATNinja and VeritasKarishma, need your help here. Can you please throw some light on options (A) and (C). IMO, (A) seems to be correct.

shobhitkh
I assume that you have eliminated other three options.
Please see detailed explanations given by fellow GC members above.

Coming to your point, please see that in A two things compared are not similar in nature one being duty assignments and the other being staff. They should be so that parallelism makes sense.
On the other hand, C on first glance may look bad but its perfectly alright both idiomatic and parallelism point of view - staffing, a gerund noun, and duty assignments are parallel.

Hope this is helpful.

Studies of the human sleep-wake cycle have practical relevance for matters ranging from duty assignments in nuclear submarines and air-traffic control towers to the staff of shifts in 24-hour factories.

(A) to the staff of
Since the bit after "from" is an action we need an action after "to", in A the bit after "to" refers to humans and not an action

(B) to those who staff
Since the bit after "from" is an action we need an action after "to", in B the bit after "to" refers to humans and not an action

(C) to the staffing of
There is no error, it correctly follows parralellism

(D) and staffing
This can't be the answer since we need a "to" because the formation is of "from x to y"

(E) and the staff of
This can't be the answer since we need a "to" because the formation is of "from x to y"