Actually, Virginia is a better answer for Ohio, through West Virginia. Also, Oklahoma has a bigger western border with Texas, so the answer should be New Mexico.
I'd certainly say so. Seems arbitrary to choose Delaware, especially since you can't get from OH to DE in a straight line, but you can from OH to NJ. I'd also argue WV has the longer border with OH.
Only spotted the small print about longest answer after I did it. How about allowing any answer that is correct? Mentally comparing border lengths is kinda tricky.
Not sure about the longest border parameter, and I also didn't see that till I was (unsuccessfully) finished. For Idaho, it could be Nebraska, South Dakota or North Dakota, depending on where in Idaho you started. So what does longest border mean? Longest border with the state in the middle, or the ending state with an overall longest border? Great concept, but confusing. I agree with Jerry928 about just allowing any answer that is potentially correct. Still makes you think!