What happens when Frequency of EM radiation decreases?

[Kainath Kamil Dis 2K]

The Textbook says " The extent of the change in the electric field at a given point decreases." I am having trouble understanding this answer and why it is not "energy of radiation decreases" or "speed of radiation decreases"

[Renga Rengappa 1D]

I believe that answer is just a graphical representation of saying the energy decreases. If you think about it in the context of the wave graph, with amplitude, frequency and slope of the wave, when frequency decreases the slope will also decrease. Thus because the slope decreases, the rate of change becomes smaller, which is basically what the textbook answer is saying.

[Emaad Sohail 3F]

Basically what the previous response said- when frequency decreases, wavelength gets longer, and the slope of the tangent line to wavelength (or its derivative) decreases too.