I don't think changing seasons can REMOVE CO2 from the air, but I do think instead it could add it to the air. It's a long process that involves several ecosystems and stuff. But, as the climate is getting warmer, ice caps are melting and within these ice caps... there are trapped bubbles of CO2 that are released ( I am not sure if this adds a lot of CO2 to the atmosphere, but I am sure that it does contribute to CO2 concentration).
In relation to your last statement... plant growth would actually reduce CO2 in the air because of the process of photosynthesis. Plants take in CO2 and give out O2 for us to breathe. In turn we conduct cellular respiration in which we take in the O2 and give out the CO2. So, plants are actually one good solution for decreasing CO2 levels.
If less is the only option then go with that like your question suggests but more feels like a better answer
The Vitamin C will probably get decreased due to the food it is processed by.
Answer - Codominance
Reasoning - Codomance since the black cat and tan cat is combined when it was breed in turn making its both able to co-dominance together. Rather having a black cat only as a dominance or tan cat.
