A nulliparous client has been admitted after 12 hours of mild contractions at home. On examination, the client is found to be fully effaced and dilated to 3 cm. Contractions are every 5 minutes and last approximately 60 seconds. The client asks the nurse approximately how long it should take to get to 10 cm dilation. Which of the following is the most appropriate response?

C Approximately 5 hours A Approximately 3 hours D Approximately 7 hours B Approximately 4 hours