would not be polluted seriously

[joham]

If we had taken such measures much earlier, the river _____ so seriously now.
A. would not be polluted B. would not have been polluted

The given answer is B. But I wonder if A is also right.

Thank you in advance.

 

[euncu]

***neither a teacher nor a native-speaker***

If we had taken such measures much earlier, the river _____ so seriously now.
A. would not be polluted B. would not have been polluted

The given answer is B. But I wonder if A is also right.

Thank you in advance.

If it was "If we took such measures much earlier", "the river would not be polluted so seriously now." would be okay.

 

[emsr2d2]

If we had taken such measures much earlier, the river _____ so seriously now.
A. would not be polluted B. would not have been polluted

The given answer is B. But I wonder if A is also right.

Thank you in advance.

The clue is the word "now". You can't say "it would not have been polluted now". You can say "it would not have been polluted last week/last month/in January/in 2006 etc etc".

The only possible sentence is "....the river would not be polluted now" (both "would not be" and "now" are in the present).

 

[Tdol]

I agree that a) is the correct answer; it's a mixed conditional for a past action (or inaction- not taking measures) with a present result (pollution).