Which of the following must be true for natural selection to occur? O A. The ecosystem cannot contain predators.
B. A population cannot have competition for resources,
C. A population must be stable.
D. The ecosystem must have limited resources,

20 points and brainlist 1. london has suffered from terrible air pollution for at least seven centuries. why is the city so prone to its famous “london fog? ” what did london do to get rid of its air pollution? 2. why does air pollution cause problems in developing nations more than in developed ones?