The correct answer should be B. decreased immigration
Immigration was not decreased, it was high and therefore people needed more land and they expanded.
D. Sextant
This question should actually sat altitude instead of latitude. But this was a instrument with a graduated arc of 60° and a sighting mechanism, used for measuring the angular distances between objects and especially for taking altitudes in navigation.
Should be TRUE, but lmk if not but I'm pretty sure it is.
