What made the Allies hesitant to invade Japan's
mainland?

The Japanese were an absolutely ferocious foe. Near the end of the war 99% of their soldier would perish before they surrendered. If they invaded the homeland of Japan, it was estimated over a million Americans at least would die.

the correct answer is: (1) affected by gerrymandering; (2) not affected by gerrymandering.

gerrymandering is known as a practice that intends to establish a some kind of political advantage for a particular party or group. to do this district boundaries are manipulated. the new resulting district is named a gerrymandering.

in other words, what gerrymandering does is to draw the boundaries of electoral districts trying to benefit the party who is doing it. sometimes, the party controlling the legislature will redraw it so they can maximize the number of districts they are likely to control.