A) No, because you’d be under the shelf of Class C airspace
B) Yes, because you’d be operating in Class C airspace
C) Yes, because you’d be operating in Class B airspace
A couple of issues impact your ability to inspect the tower in question. 1) needing an airspace authorization if you’re going to enter controlled airspace, and 2) remaining within a 400 ft radius of the tower if you’re going to higher than 400 feet AGL.
The image below shows the tower in question has a height of 1,548 ft MSL which automatically puts it on top of the tower in Class C airspace which starts at 1,300 ft MSL. So, if you want to inspect the ‘top’ of the tower, you’ll need to have an approved airspace authorization.
Additionally, Part 107.51 states that you are allowed to fly 400 ft above the uppermost part of the tower as long as you remain within a 400 ft radius of the structure, however, you’ll still have to have an approved airspace authorization if you enter controlled airspace.
So, you’re allowed to fly higher than 400 ft AGL if you inspect a structure and remain within 400 ft radius of the structure. You’re even allowed to fly 400 ft above the top of the structure (maintaining 400 ft radius) and if the altitude is going to cause you to enter controlled airspace you’ll need an airspace authorization.