In Figure 6B-1, the Northern Plains, farther away from the low-pressure system and fronts, experienced a much different air mass than that in the Middle Atlantic. What evidence can you gather from the surface observation network to support that statement? a.Calm winds were reported in multiple states of the Northern Plains. b.Many stations in the Northern Plains reported clear skies. c.Many stations in the Northern Plains reported cooler temperatures and lower dewpoints. d.Both choices b and c are correct. e.None of the above