What purpose do sentences 3 through 6 serve in this paragraph?

(1) my family has a quaint cottage at a small, private lake. (2) the cottage is about 75 years old, but we try to keep it in good condition. (3) the outside is white with green trim on the windows and shutters. (4) in front of the cottage is a flagstone walk that leads down to a stone patio. (5) the patio itself is right next to the water. (6) out from the patio stretches a dock where we keep a small rowboat tied. (7) every summer, my family sets aside a week when we all get together at the lake for a family vacation/reunion.

a. they set up a comparison.
b. they show cause and effect.
c. they provide supporting details.
d. they introduce the main idea.

Read the excerpt from elie wiesel’s all rivers run to the sea. why were those trains allowed to roll unhindered into poland? why were the tracks leading to birkenau never bombed? i have put these questions to american presidents and generals and to high-ranking soviet officers. since moscow and washington knew what the killers were doing in the death camps, why was nothing done at least to slow down their “production”? that not a single allied military aircraft ever tried to destroy the rail lines converging on auschwitz remains an outrageous enigma to me. birkenau was “processing” ten thousand jews a day. stopping a single convoy for a single night—or even for just a few hours—would have prolonged so many lives. based on the paragraph, the author would most likely agree that it is best to avoid confrontation at all costs. people need to be proactive when they witness an injustice. countries should remain neutral to keep alliances strong. moscow and washington are to be blamed for the holocaust.