Humans!
Recent scientific evidence suggests that during the starving time, the residents of the Jamestown Colony resorted to cannibalism, that is, the eating of dead humans.
Eventually, the growing of tobacco took and Jamestown was able to take hold as a successful colony but during the starving time, Jamestown went from 500 colonists to 60.
D. They led small, surprise attacks on British troops.
Fire was discovered back when we were starting to develop back in the Neanderthal stage. We used a flint rock and a piece of steel and we found sparks but we were kinda monkey looking creatures that were hairy.
I am going to guess that it would be a loss of memory.
I believe it is the conquest of Constantinople.