Given stack sizes I'd expect A5/56 to c/r turn some reasonable % of the time, to try and build a pot. Unless he thinks you're mega bluffy.

45/55 can definitely get to the river this way.

Given your river sizing, I'd say he might assume you don't have 5x. I wouldn't be too shocked to see someone capable of value raising light and have A2/A3/A4 here.

After your sizing and pot odds and possibility of him raising for value with worse, I end up calling here.

Either way you should definitely be better on the river.