Given two sedimentary layers whose grains were eroded from the same source area, the layer with the grains would be located farther from the source area.

reflecting point a across the origin negates both of its coordinates.

b = (5, -4)

radiative zone

explanation    

radiative zone is the layer of the sun which energy is transferred away from the core by radiation. although, the core is the only part of the sun that produces an appreciable amount of heat through fusion. in fact, 99% of the energy produced by the sun takes place within 24% of the sun's radius.