Confusing SAT Writing Questions

[Postponing it because of stormy weather,] the D-Day invasion of France began at 6:30 A.M on June 6, 1944.
A: Postponing it because of stormy weather,
B: It being postponed due to stormy weather,
C: Having been postponed because of stormy weather,
D: Stormy weather had postponed it, because of this
E: Due to stormy weather postponing it,

*** Shouldn’t the answer include “due to” because it needs to modify a noun- stormy weather? I do understand that C has a modifier.
ANS: C

Endowed with powerful bodies, large claws, and piercing teeth, mountain lion are one of the most formidable wild creatures native to North America. No error.

*** What should be in C?
ANS: C

The city of Conway, Wales, now surrounds the medieval walls and castle that originally enclosed and protected it. No error.

*** The city surrounds the medieval walls and castle. What does it modify?
ANS: E

For #2, the sentence refers to mountain lions as “creatures” which is plural. Thus, it should be “some of”. Also, I think “mountain lion” should be “mountain lions.”

yes, mountain lions***

For the last question: The castle used to surround the city, but now the city has grown outside of the castle. “It” is the city.

Actually for #2 the reason ‘C’ is the correct answer is because “mountain lions” is plural so referring to such a subject as “one of” (which is singular) is grammatically incorrect. “Among” or (as PSAT2014TAKER said) “some of” could work as well.

1 is grammatically correct. "Because" serves the same purpose as "due to". It correctly sets up the sentence to give a reason for why the D-Day invasion was postponed.