Flatworm get most of their oxygen through diffusion.
Option no. 2 a decrease in the release of oxygen gas
It is not simple because the process of growing crops, it needs more fertilizers, and processing the plants converting it to fuels needs a lot of energy. As much energy is used during the production from natural gas. The way of making biofuels it contains cellulose. Cellulose

velocity is a vector so it has a magnitude and direction so the answer would be B
Extinction DIF; Having no more existing or living members