It doesn't matter... contextually, "next to it" is what matters (the principle of proximity), biologically, if it's red, and the font is bold (wide) enough, both distances are fine:

This is a "foveated image" (created using Photoshop's lens blur with a radial gradient focusing on the left part of the first field, with fovea focus expected to be roughly 1 cm on my monitor). Long story short, this is what the user actually sees.
In case you need background material, Chapter 6 from Designing with the Mind in Mind is there for you (along with a few other books). Specifically, Jeff Johnson's examples Figure 6.8 and Figure 6.9 are both of your scenarios, and he says both of them are fine.