Re: Many economists believe that policy officials at the Federal

hi amit,

in the original sentence HIGHLITED part is a modifier....set between the commas.
and after the modifier VERB are==>is acting as a verb for the subject economists....which is correct.

Many economists believe that policy officials at the Federal Reserve,now seeing the economy as struggling with negative growth and high inflation, are almost certain to implement further rounds of quantitative easing in the near future.

now if you just fit option B the original sentence becomes:

Many economists believe that policy officials at the Federal Reserve,now seeing the economy to be struggling with negative growth and high inflation and are almost certain to implement further rounds of quantitative easing in the near future.

in this option...the part starting with now seeing the economy....is acting as modifier..moreover because of the removal of comma before are..that part is also coming under MODIFIER part....hence the verb for the subject IS MISSING...
thats the major ERROR in this part.

hope it helps