Well, they all are used in C-41 colour film development.
The part A K carb is the alkali - it sets the pH to allow the developer to work best, and at a rate that suits the three dye forming layers that are developing at the same time in all colour integral films.
The part B HAS is a dye restrainer of some manner, I recall form memory. My detailed notes are not close at hand. I believe it keeps dye development from one layer spilling into the next layer, but am not sure of the mechanism of how this would work to explain it.
The part C is a complex salt of PPD that is the colour developer agent. Likely CD-4. It is likely also in with some oxidizer inhibitor to keep it from going off all on its own. In colour film development the oxidation products of this long chain organic molecule link up with clear dye former elements manufactured into the film. When the oxidized developer component hits the dye former, a visible dye is created.
With ongoing use of a solution, the byproduct of previously developed films remain in the solution, and parts of the original soultion are partially exhausted. Repenishers restore the chemistry back to a balanced situation. The byproducts of developing a film are the silver salt ions: Bromide, Iodide or chloride (likely mostly the first two here). The colur developing agent is partially used up. I never thought of HAS being used up, but it is an organic, so it certianly can be.
Frequently chems are sold as replensihers, and a starter is added to mimic the effect of films being processed before the first films have been run in a new tank of chems.
As to the chemicals you have, without dilution or useage rates, you are rather stuck as to how to use them.
As to disposal, the carbonate can be thought of as a laundry booster for extra dirty loads.
The HAS and PPD solutions should be aerated to decrease thier BOD levels (ie wanting to take oxygen out of the water) It may be better to just turn them in as hazardous waste.