What power sources did humans use before and during McCoy's era?

People used animal power, mules, oxen, and horses.
People used wind power, used to pump water from wells.
People used water powered mills used to grind grains and cut lumber.
all of the above

in ray bradbury's short story "a sound of thunder", mr. eckels's fearfulness leads to drastic consequences for the rest of the world.

in the story, mr. eckels, who is a hunter, hires a time travel company to travel to the age of dinosaurs. although he is excited for the hunting expedition at the beginning, when they reach there and mr. eckels sees the tyrannosaurus, he feels frightened. as he is afraid of the tyrannosaurus, he steps off the path although he has been warned not to do it. by stepping off the path, the entire course of the future is affected: mr. eckart alters the future by stepping on a butterfly, which causes a new man to be elected president in the future. in that way, it is mr. eckart's fearfulness what triggers 'the butterfly effect' and what leads to drastic consequences for the rest of the world.

what is the sentence?

you should start by saying what they did to these subjects hope that this

ok so it would be d because that would catch attention and make them what to read it.