The connotation that best matches the word jostling as it is used in this excerpt is B. Disordely and anxious.
The idea conveyed in the excerpt is that the character is on the verge of being caught by this <em>ever growing army of people</em>. The word <em>jostle</em> is usually used when someone is mentioning a crowd, because it also conveys this idea of being chased, pushed and shoved by it.
B. A prediction of the consequences for the position I'm assuming that means a counter-argument, which is important for persuasive and argumentative essays.