The men who alerted the Boston area to the arrival of the Regulars were Paul Revere and Williams Dawes.
C. They were laws that segregated blacks and whites in the south
The correct answer is option B.
Edmond Halley correctly predicted the return of the eponymous comet Halley after he realized several sightings of a comet were in fact the same comet.
By correctly understanding Sir Isaac Newton's law of gravity and also his ideas in mathematics, Halley was able to correctly predict that the comet that now bears his name would return periodically. He did this by discovering Halley's orbit in 1716 and thus being able to predict the year of its return.
The Homestead Act was attractive to settlers, because it gave land to anyone over 21, or head of family (even women and former slaves), who applied for land, this land for a very cheap price (or no price at all) and through this it enabled easy settlement. The farmers had to then cultivate the land for a period of time, and if they did not abandon it and tended to it properly, it became their property.