A, B, and C are his basic choices. But D is more and more likely at this point. And D is his removal from office by some method....death, arrest, exile, resignation. And the longer he sticks with C, which seems to be his decision for now, the more likely D becomes.
The Kharkiv rout highlights a few critical things that we sort of knew but have been driven home over the space of two short weeks:
First, Russia's real adversary at this point is headquartered not in Kyiv but rather Washington and Brussels. A flood of Western aid and high-tech weaponry is now providing Ukraine a decisive advantage. For example, I assume the Kharkiv operation was supported by real-time American intelligence and advice.
Second, after months of significant losses, the Russian invasion force is badly overstretched, inadequately equipped, poorly commanded, and seriously demoralized. There've been no battlefield gains in many weeks. The supposed objective of taking the whole of the Donetsk region has not gotten off the ground and may now be doomed by the loss of the entire northern axis to Ukraine.
Third, the leadership in Moscow is in a state of serious disconnect and denial. Putin keeps replacing commanders, but the problem goes deeper than that. Russia's strategy from the beginning has been seriously flawed, undermined by bad intelligence, and based on the spectacularly misguided premise of a quick Ukrainian capitulation. Russia bargained for a short war against Ukraine and instead got a long war against NATO. No commander in history can overcome that kind of miscalculation.
In light of the above three factors, time is now working against the apparent fallback strategy of consolidating gains and digging in for the long haul. I don't think a Russian defeat is imminent, but it may be inevitable unless the plan changes. Even so, as expressed in the OP, I still believe neither Ukraine nor Russia can emerge from this mess a "winner." However, another two weeks like the last two weeks may cause me to rethink that opinion.