For numbers 1 to 4: A physician is interested to determine if the mean length of waiting time to conceive (in months) of married women in urban and rural areas is the same. She randomly selected 10 married women in each area matched according to age at marriage and parity. The length of waiting time to conceive since data of marriage or date of last birth delivery was recorded. 2. Which of the following is(are) TRUE? I. A necessary assumption for the parametric test to be valid is that the difference in lengths of waiting time should be normally distributed. II. The parameter of interest is the proportion of married women in urban and rural areas. O A.I only O B. II only O C. Both I and II O D. Neither I nor II