I’m pretty sure the answer is c and d hope this helps and good luck
λ=v/f
λ-wavelength
v-speed
f-frequency
we have the wavelength(6.2 x 10^-6meters) and we use the speed of light which is equal to 3*10^8m/s
6.2*10^-6m=3*10^8m/s/f
f=(3*10^8m/s)/(6.2*10^-6)≈0.48*10^14Hz
Technically speaking, there are many "levels" of a plant for which this may hold true. I think the one you are referring to is the chloroplast. It takes in the light energy from the sun, water and carbon dioxide, and performs photosynthesis on them to produce sugar and oxygen. A leaf would also fit the description as this is a very general question.
