Answer:
It's D: 1,2,3,4,5.
Step-by-step explanation: A natural number is a positive number that is not 0, and choices A and B have 0 in them, so we can eliminate those choices. For choice C, the question says that x is a natural number less than 6, so it can't include 6. So, we can eliminate Choice C and we are left with Choice D. Your answer is D. Hope this helped