Which of the following is a complex sentence? a. check out the editorial page in today's paper and you'll notice the piece by george will. b. i simply cannot make heads or tails of rap lyrics, but i suppose i'm just too old to understand them. c. as jake was reading the email from june yet again, the flight attendant coughed gently to get his attention. d. i would like to visit the kinshasa, but i understand the city is unsafe for foreigners.