一道GWD的题
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.

• heavily accounts for almost half of the $20.8 billion increase in drug spending last year, the remainder of which came[C1]
• heavily were what accounted for almost half of the $20.8 billion increase in drug spending last year; the remainder of the increase coming[C2]
• heavily accounted for almost half of the $20.8 billion increase in drug spending last year, the remainder of the increase coming [C3]
• heavily, accounting for almost half of the $20.8 billion increase in drug spending last year, while the remainder of the increase came[C4]
• heavily, which accounted for almost half of the $20.8 billion increase in drug spending last year, with the remainder of it coming