Which of the Following Provided the Selective Pressures That Most

Which of the following provided the selective pressures that most directly promoted the evolution of photosynthesis?

A) the drop in surface UV radiation caused by the formation of the ozone layer
B) the depletion of dissolved organic material from the oceans
C) the ability of some organisms to use oxygen to generate ATP during respiration
D) an increase in visible light intensity at the surface of the Earth, caused by solar flares
E) an increase in volcanic activity and release of CO₂ into the atmosphere