Which of the following sentences uses the correct subject/verb agreement?

a. we could tell in a moment that her rock and support through her trials were her mother.

b. my sister and best friend is going to be my assistant at the booth.

c. the happy father claimed that his pride and joy are his son.

d. his effort and hard work are just one sign of the extreme effort he put into this project.

The main themes of the play are: fate and free will with the inevitability of oracular predictions is a theme that often occurs in greek tragedies the conflict between the individual and the state similar to that in sophocles’ “antigone” and   people’s willingness to ignore painful truths both oedipus and jocasta clutch at unlikely details in order to avoiding facing up to the inceasingly apparent truth and sight and blindness the irony that the blind seer tiresius can actually “see” more clearly than the supposedly clear-eyed oedipus, who is in reality blind to the truth about his origins and his inadvertent crimes.