This reduces biodiversity.
a: agricultural intensification
b: the eu
c: traditional farming practices
d: use of chemical agents

I believe its either A) Agricultural intensification, or possibly D) Use of chemical agents. I've heard that both can cause a drop in biodiversity, but i'm not completely sure.
Hope this helps~!
~{Isle of flightless birds}

Migration people get up and go cause they feel it is best for them