Help with 10

Hi Christina81, thanks for reaching out. The correct answer for this question is actually E, so I am bit confused by the question. Maybe mistyped or I am misunderstanding. But regardless, the reason that E is correct is that the digits 2 and 4 can never be separated by more than 2 slots. Whereas 2 can be the first slot while 3 can be the last, which falsifies the answer choice that there can be at most two digits between 2 and 3. I hope this helps. Please let me know if you have any other questions or would like me to elaborate further!