I came across this question on internet.

For the below question I have doubt on the usage of coming in the [c] below.

Can you please clarify if "increase coming" is correct ?

According to a recent study of consumer spending on prescription medications, increases in the sales of the 50 drugs that were advertised most heavily accounts for almost half of the $20.8 billion increase in drug spending last year, the remainder of which came from sales of the 9,850 prescription medicines that companies did not advertise or advertised
very little.

A. heavily accounts for almost half of the $20.8 billion increase in drug spending last year, the remainder of which came
B. heavily were what accounted for almost half of the $20.8 billion increase in drug spending last year; the remainder of the increase coming
C. heavily accounted for almost half of the $20.8 billion increase in drug spending last year, the remainder of the increase coming
D. heavily, accounting for almost half of the $20.8 billion increase in drug spending last year, while the remainder of the increase came
E. heavily, which accounted for almost half of the $20.8 billion increase in drug spending last year, with the remainder of it coming

A. heavily accounts for almost half of the $20.8 billion increase in drug spending last year, the remainder of which came
the remainder of (what??) not the last year but the "increase in sales"
B. heavily were what accounted for almost half of the $20.8 billion increase in drug spending last year; the remainder of the increase coming
Incomplete sentence
C. heavily accounted for almost half of the $20.8 billion increase in drug spending last year, the remainder of the increase coming
the remainder of (what??) not the last year but the "increase in sales"
D. heavily, accounting for almost half of the $20.8 billion increase in drug spending last year, while the remainder of the increase came
E. heavily, which accounted for almost half of the $20.8 billion increase in drug spending last year, with the remainder of it coming
which accounted for almost - incorrect usage .

Hence D