Legally, it depends on what you were arrested for. (The London Embassy site oversimplifies this).
The main factor is whether the crime (and just being arrested is sufficient, even if found not guilty) involves 'moral turpitude'. That is not synonymous with 'serious' - anything theft, sex or drugs related is moral turpitude for a start, but assault is not necessarily, for example. Nor are most motoring offences - not even drunk driving.
If the crime was not moral turpitude, then you can truthfully tick the no box on the form and get in.
If it was, then legally you have to apply for a visa, which you may not get.