Which kind of complement is the underlined word?

how long have you played piano?

a.
predicate nominative

b.
direct object

c.
predicate adjective

d.
indirect object

Which sentence contains an allusion? a. pamela and her twin are as alike as two peas in a pod, and they do everything together. b. pamela has a weakness for chocolates, which she says she's had since early childhood. c. pamela's face was as white as a ghost when she learned the shocking news about her brother. d. pamela's backyard looks like the garden of eden, with dozens of green and lush plants. e. pamela found herself trapped between a rock and a hard place, and she didn't know what to do.