I believe the answer is D) The mean cannot be determined from the available information.
The mean in math means the sum of all the numbers divided by how many numbers there are. There is no information about how many numbers there are nor any information of which numbers exist and which numbers don't.
The data set only tells us the first number, last number, and median-- things a box-and-whisker plot would tell us; perhaps a different way of representing data would work better to help us find the median like a dot plot or a bar graph.
If this is incorrect, please, don't refrain to tell me. Thank you.