As pavement separates, weeds like mustard, shamrock, and goosegrass blow in from Central Park and work their way down the new cracks, which widen further. In the current world, before they get too far, city maintenance usually shows up, kills the weeds, and fills the fissures. But in the post-people world, there's no one left to continually patch New York.
Which sentence best states the main idea of this section of the chapter?
A. Weeds are uprooted by hand because herbicides are environmentally unsafe.
B. Three main types of weeds are known to grow in New York's Central Park.
C. Invasive weeds are kept at bay by city crews who are paid to uproot them.
D. Tax dollars will not always be available for maintenance crews to kill weeds.