The relationship between frequency and wavelength for an electromagnetic wave is

where
f is the frequency

is the wavelength

is the speed of light.
For the light in our problem, the frequency is

, so its wavelength is (re-arranging the previous formula)
Answer:
"What is the best advice a parent can give a child?"
Explanation:
The other answers have one clear response. Ex: Orange popsicles melt faster than grape popsicles. That would be a fact.
But parental advice can vary, depending on your opinion. I may say that all parents must teach their children not to talk to strangers, while someone else may say that parents should advice their kids to treat everyone fairly. Nothing can be proven as the only appropriate response.
Hope this helps!
They share covalent bonds