1. (D) The loneliness of human beings
2. (A) The heron feeding on the snake in the pond
3. (D) The rabbits are part of George and Lennie's dream of one day having a farm of their own
=)
"Impact" is an effect.
So "impact" of the death means: the effect that death has on something.
For example, you could say:
The Impact of the death of the Emperor was the loss of respect for the country from the neighboring countries.
or you could say:
The impact of the death of her mother on her was devastating.
