I would go with E too.
'Much' is used for things that can not be counted. e.g 'too much of exercise', 'much heavier', 'too much to talk' etc.
Since '20% of young adults' is a number, E would be the right choice.
I beg to differ here. Although the correct option is E its not for the reason quoted above.
20% is not a number since we dont know 20% of what. Hence much will be used along with any estimate stated in percentage. Had it been 20% of 1000 youth then many would have been appropriate.
as much as 10% of smokers die due to lung cancer..... (correct).
as many as 10% of smokers die due to lung cancer..... (Incorrect)This is my own opinion.
Let me know counterviews if any......
I do not suffer from insanity. I enjoy every minute of it.