Hi mukherjee,

The sentence requires a cause-effect construction. Worker's cost to the nation is the direct
effect of the lost work days. We should highlight that meaning.

E) we have two errors here, the first is a modifier error, which after the comma modifies years
and we don't that beacuse the years are not costing money to the nation. The second one is
that the word cost for parallelism rules is applied to both the first item "50b in lost medical
expenses" and the second item "lost work time", risulting in an awkward and redundant
construction "cost lost".

D) Subject-verb agreement error, "costs" should be plural.

C) "so as to" is used to express purpose, thus its usage here is wrong.

B) correct

A) the use of "they" is ambiguous it can refer both to "64m workdays" or to "18m Americans".

-tathastuGMAT