Your answer is C, in the past.
In "A Pair of Silk Stockings," the silk stockings are a symbol of C.) MRS. SOMMER'S SELFISH NEEDS.
Instead of buying the things needed by her children from the little money she got, Mrs. Sommer's opted to buy the silk stockings she found while searching for items needed by her kids.
She was drawn to buy it because it gave her the illusion of being a rich lady with no worries in the world. The silk stockings gave her the chance to live her fantasy.
C is the choice I would make because I believe the writer is planning to answer this question: "and how come we think dogs are so smart". The writer never tells us what dogs can't do (a) or mention others being dumb (b) and doesn't make fun of humans (d)
