Which sentence uses commas correctly?

a.
hearing her worried cries, we attempted to rescue the cat stuck in the tree.

b.
during the rescue several small branches, fell to the ground.

c.
while we are waiting, for the fire department, do not climb the tree.

d.
hey let's try to tempt her down, with some cat food.

Which best explains this excerpt’s purpose in the novel’s plot structure? the excerpt creates conflict between characters as part of the rising action. the excerpt provides background information on a character as part of the exposition. the excerpt returns a character to equilibrium as part of the falling action. the excerpt is the point of greatest tension and acts as the climax.