Thanks to the measures ______ by the local government , the polluted river is becoming clearer and clearer and fish have begun to show up in it.

Thanks to the measures ________ by the local government, the polluted river is becoming clearer and clearer and fish have begun to show up in it.

A．taking 

B．taken

C．to take 

D．having taken

Thanks to the measures ______ by the local government , the polluted river is becoming clearer and clearer and fish have begun to show up in it.

1. A.
   taking
2. B.
   taken
3. C.
   to take
4. D.
   having taken

Thanks to the measures ______ by the local government , the polluted river is becoming clearer and clearer and fish have begun to show up in it.