Using a good compound bright field microscope with a resolving power of 0.3 μm, a 10× ocular lens, and a 100× oil immersion lens, would you be able to discern two objects separated by 3 μm? 0.3 μm? 300 nm? 3000 Å?

Yes, it could discern all of them.

Explanation:

A compound bright field microscope can be used to illuminate samples in light microscopes. It has a very high resolution and it could detect samples as small as 200 to 300 nanometers. So, yes it could discern two objects separated by 3μm, 0.3μm, 300nm,3000Å.

option number c is the right answer.