Concept:Nullification of ablution (al-wudu) occurs when a specified impurity or natural bodily discharge takes place.Explanation:Among the listed actions, urinating is a discharge that breaks wudu.Sneezing, singing, and drinking do not nullify wudu in Islamic rulings.Urine is considered a major impurity, and its exit from the body invalidates ablution.Therefore, the correct choice is the one that refers to passing urine.Answer:D. urinating