Rewrite the sentence, correcting the verb if it does not agree with the subject. if the sentence is already correct, write correct. The group are meeting to discuss which poem to use.
pls help me with this.
I need the answer know.

1. in which sentence is the underlined portion a predicate nominative? for astronauts, going into space to repair orbiting equipment becomes a challenge. for astronauts, going into space to repair orbiting equipment becomes tricky. for astronauts, going into space to repair orbiting equipment becomes challenging. for astronauts, going into space to repair orbiting equipment becomes frequent.