a 'and' is required before 'fatigue' for proper structure
b not parallel

'lowered' is redundant in D and E.

c shd be the answer

is it B

IMO C

pradeepkaushal9518 wrote:plz explain

Recently implemented "shift-work equations" based on studies of the human sleep cycle have reduced sickness, sleeping on the job, fatigue among shift workers, and have raised production efficiency in various
industries.

(a) fatigue among shift workers, and have raised
(B) fatigue among shift workers, and raised
(C) and fatigue among shift workers while raising
(D) lowered fatigue among shift workers, and raised
(E) and fatigue among shift workers was lowered while raising

The skeleton of the sentence:

Shift-work equations have reduced X, Y, and Z while VerbING.

Key point:

Have reduced X, Y, and Z-here X, Y, and Z are the elements a list of the items that have been reduced by equations. Before the last item of the list we should use "COMMA + AND". Since the last item of the list is "fatigue", we should look for the options where there is AND. A, B, and D are eliminated because they don't have the final AND.
We are between C and E. In the option E, "was lowered" makes the sentence a breakage one. If we say "M has reduced X, Y, and Z was lowered", it loses the parallelism. So, E is out.

Answer is C.

NOTE: While can be used in the middle of the sentence with and without having a comma before it.
I'm walking while you're running = I'm walking during the time you're running
I'm walking, while you're running = I'm walking whereas you're running