Option 1: Insolation refers to the amount of solar radiation reaching the Earth`s surface. While it`s true that the equator receives more insolation than the poles due to the direct angle of the sun, stating it`s roughly 10 times more is an overestimation.

Option 2: Infrared rays do account for a significant portion of insolation, but saying they constitute roughly two-thirds of it is not accurate. The majority of insolation is actually visible light.

Option 3: This is the correct answer. Infrared waves are indeed largely absorbed by water vapor, which is concentrated in the lower atmosphere. This absorption helps warm the Earth`s surface.

Option 4: This statement is incorrect. Infrared waves are not a part of the visible spectrum of electromagnetic waves of solar radiation. They fall just outside the visible spectrum, with wavelengths longer than visible light but shorter than microwaves.