C. Plans are useful, but so is flexibility. Lolll
Lord and Lady Capulet both have strong emotional reactions to Juliet's refusal to marry Parris. When Juliet gives her answer, Lord Capulet gives her an ultimatum: marry Parris or he'll disown her. Lord Capulet does not have a rational conversation or hear Juliet's concerns. Lady Capulet also reacts emotionally when she refuses to listen to her daughter as well.
It is a compound sentence, because this sentence consists of two independent clauses ('the lamp fell over' and '(the lamp) scared the cat"). Simple sentence would have only one independent clause.