ahh !! this is typical of "NO COMMA+VERBLESS" clause, unlike the question that you have posted
C (in official question) says:
Recently implemented "shift-work equations" based on studies of the human sleep cycle have reduced sickness, sleeping on the job and fatigue among shift workers while raising production efficiency in various industries.
NOTE that : in NO COMMA+ VERBLESS clause, as is in above mentioned option C, the verbless clause takes the SUBJECT of the previous clause as its subject (PLUS there is no ELIGIBLE noun other than "
Recently implemented "shift-work equations" in previous clause)
the implied meaning of option C is :
Recently implemented "shift-work equations" based on studies of the human sleep cycle have reduced sickness, sleeping on the job and fatigue among shift workers while[Recently implemented "shift-work equations" are] raising production efficiency in various industriesthe question that you have created is typical of
"COMMA+ VERBLESS CLAUSE"; in such construction the "verbless clause" takes the preceding NOUN or NOUN PHRASE as its subject
ALSO note that WHILE is a beautiful word : it can introduce
"simultaneity" and
"CONTRAST". again the usage of "COMMA" makes a huge difference !!