At which wavelength does a red solution transmit light?

A red solution primarily transmits and reflects light in the longer wavelengths of the visible spectrum, which correspond to red hues. In the context of the choices given, the 600-650 nm range is associated with red light.

When we observe a red solution, it absorbs wavelengths of light in the blue and green regions of the spectrum, which typically range from about 400 to 550 nm. The wavelengths in the 600-650 nm range are those the solution transmits, meaning that it allows this light to pass through rather than being absorbed. This is why a solution, appearing red, actively transmits light predominantly at these wavelengths.

The other ranges provided would include wavelengths that do not fall into the red spectrum, which explains why they are not suitable answers for the question regarding transmission of light by a red solution.