1999 Ford Ranger P0352 DTC: Ignition Coil B Primary/Secondary Circuit Fault - Which Coil Is 'B'?

I own a 1999 Ford Ranger with the 2.5L 4-cylinder engine and recently received a Check Engine Light diagnosis showing DTC P0352: "Ignition Coil B Primary/Secondary Circuit Malfunction." The truck runs smoothly otherwise, but the persistent warning light is concerning. This engine uses two ignition coil packs, so I suspect one of them is faulty. However, I'm unable to determine which coil corresponds to 'B' in the code — this information isn't clearly documented in any available resources or service manuals. A Ford dealership technician suggested that I may need to replace the ignition module as well. While I understand that the module can fail, I’m confused: if it were completely failed, I’d expect multiple diagnostic errors beyond just P0352. The fact that only one code is present makes me question whether a full module replacement is necessary. I'm looking for reliable guidance on how to identify which coil pack corresponds to 'B' and whether the ignition module should be replaced. Any advice or troubleshooting steps would be greatly appreciated — especially from experienced mechanics who have worked with older 1999 Ford Rangers.