I would say B.
A, umm, don't crash trains, that's bad.
C, Lillian is wondering how fast a train can go, not at what curve will it fall.
D, Lillian isn't wondering about the size of the trains, just the speed.
Answer:
B. increase biodiversity
It can't increase the biodiversity it can effect the biodiversity
B. The compass shows south is down & North is up the south wind will blow stronger up.
