Concept:Median is the middle value of an ordered data set. For an even number of observations, the median is the average of the two middle values.Explanation:Arrange the numbers in ascending order: 7, 8, 9, 10, 11, 12.Total observations n=6, which is even.The middle positions are the 3rd and 4th values.3rd value = 9, 4th value = 10.Median = 29+10​=9.5.Answer:9.5 (Option D)