Final answer:
The first stage of labor, which is the dilation stage, usually lasts 18-24 hours for a primigravida and 6-12 hours for a multigravida.
Step-by-step explanation:
The first stage of labor and delivery is known as the dilation stage, where uterine contractions and cervical dilation occur. For a primigravida, a woman who is pregnant for the first time, this stage generally lasts from 12 to 20 hours or even longer. In contrast, for a multigravida, a woman who has previously given birth, the first stage of labor tends to be shorter, taking approximately 6-12 hours. Therefore, the correct answer to the question is: c) 18-24 hours for primigravida, 6-12 hours for multigravida.