The speaker of snow-bound view memory as something beautiful that he should alwyas hold into, which remind him about what he cherish in life.
This is very similar to lily who lay on top of ponds, who provide esthetical value and a place for others to hold on to.
In my opinion, the correct option is 4. It was natural on that golden evening that I should jump at the idea of a social paradise. The narrator seems to imply that the idea of a social paradise seemed logical from all he saw there. But the very fact that it only seemed so tells us that it wasn't really true. The things he saw made him jump to a wrong conclusion. The other sentences don't imply that these assumptions were incorrect.
To survive, like find shelter, food, water and anything they possibly need to survive.
Think of it this way.
"His shoddy frock and mobile cigar have also brought its share of laughs."
And
"His shoddy frock and mobile cigar have also brought their share of laughs."
Which one sounds better?
I'd say the first time, but that's just me. x
The answer is C.) Text that artfully engages the reader I hope I helped you