C. crossing over This is because each gene have a piece of each other Hope this helped=)
A seems most likely, check with others if u have the time
Oxygen cycle The cycling of oxygen between the biotic and abiotic components of the environment (see biogeochemical cycle). ... In the process of respiration oxygen is taken in by living organisms and released into the atmosphere, combined with carbon, in the form of carbon dioxide.
I would answer your question but i think you wanted to add options. next time you can just screen shot and actually i think you still can by pressing the edit button. And there are several types of wedges you could be talking about mechanical, frost, salt, etc.
You need to be a bit more specific. but i would be more than happy to answer your question. :)