Which of the following bands may provide long-distance communications via the ionosphere's F region during the peak of the sunspot cycle?

Answer: A. 6 and 10 meters

During the sunspot peak, the F region can become ionized enough to reflect 6- and 10-meter signals over long distances. The 70 cm, 1.25 m, and 23 cm bands are too high in frequency for that.

Tip: More sunspots, higher usable frequencies: 10 m and even 6 m open up.