Is there anything I can do in Audacity to get A or C closer to B?
No. But there’s quite a bit you can do to the room. You have echoes from the walls and floor. A and C have that “recording in the bathroom or kitchen” sound. That and noise are the curse of first-time home recordists. You have the noise licked.
There are no effective post production filters or corrections for echoes or reverb.
There are products you can buy to provide some echo suppression. This one claims you can take it on a plane with you.
I made a “home” version of that from hardware store parts.
For a while there, Home Depot had pre-cut 24" pipes which could be pressed into service. See Text.
Microphone spacing is a big deal. In general, a Hawaiian Shaka for direct recording.
Or a power fist with a pop and blast filter.
Heavy Is Good in soundproofing. Those moving blankets weigh 17 lbs each. Someone posted a design podcast for making acoustic wall panels out of heavy bath towels. I really need to go find that post. He posted before and after sound tests.
You sound close enough by just making the room “go away” when you perform.
We can do a quick evaluation when you get closer by posting a ten second sound test.
https://www.kozco.com/tech/audacity/TestClip/Record_A_Clip.html
I do evaluation from the point of view of Audiobook voice specifications. In general, if you can pass that, you can post anywhere.
Good luck.
Koz