How is the underlined pronoun used in the sentence?

((who)) at the park left a pair of mittens on the ground?

a.
subject

b.
direct object

c.
possessive

d.
object of a preposition

Which line of dialogue best describes mrs. x’s sense of superiority over miss y at the begging of the play? a. “if you wanted to shoot me it wouldn’t be so surprising, because i stood in your way.” b. “home is the best of all, the theatre next and children—well, you wouldn’t undertake that.” c. i embroidered them myself—i can’t bear tulips, but he wants tulips on everything.” d. it’s sinful to sit here and make fun of ones husband this way when he is kind and a good little man.”