The nurse is teaching a client who is 28 weeks pregnant and has gestational diabetes how to control her blood glucose levels. Diet therapy alone has been unsuccessful in controlling her blood glucose levels, so she has started insulin therapy. The nurse should consider the teaching effective when the client says（）
A. "I won’t use insulin if I’m sick. "
B. "I need to use insulin each day. "
C. "If I give myself an insulin injection, I don’t need to watch what I eat. "
D. "I’ll monitor my blood glucose levels twice a week. "