This is a nice idea. I zoomed out far enough that the letters felt about the same size as I would code with (i.e., about 8-10 pt) because I think that gives me a better feel for the recognition differences of the letters.
At that size, the differences between the letters in version (a) are not as easily recognizable as they are in (e) and (d). Also at that size, the serif at the bottom of the 1 in (c) is too small to be really noticeable and the l character might look too much like a 1 if you didn't have a 1 nearby for comparison.
This is a nice idea. I zoomed out far enough that the letters felt about the same size as I would code with (i.e., about 8-10 pt) because I think that gives me a better feel for the recognition differences of the letters.
At that size, the differences between the letters in version (a) are not as easily recognizable as they are in (e) and (d). Also at that size, the serif at the bottom of the 1 in (c) is too small to be really noticeable and the l character might look too much like a 1 if you didn't have a 1 nearby for comparison.
I'm leaning towards (b) and (e). :-)