Based on observations of fossils of glossopteris, wegner that this continent a. magnetic reversals had occurred in earth's past b. continental rocks containing these fossils had once been joined c. earths continents were never joined d. glossopteris grew only in the tropics

Based on observations of fossils of glossopteris, Wegner concluded that this continent was continental rocks containing these fossils had once been joined. He had thought this based on his observations, and based on this, this would actually be the reason to why he thought that this would be why the rocks would come together and join. He was first observing the fossils of glossopteris, which then he made a hypthosis first, and then he had concluded with facts and why this and that had happened. And therefore, your correct answer would then be (option b).

Answer decreased soil salinity;

Answer volcanic outgassing;