C. Directions: Write a sentence using the personal pronoun. Make sure to show the antecedent in it. (I would like to see your wonderful answers! Grade 4 or not let's see what you learned in school!)

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.