Well, there is only one realistic answer. Option One is when you take the DNA of two different people or creatures and combine them into one organism. Cloning wouldn't prove anything here, "hybridization" is weird - but it doesn't have anything to do with the situation. So only only remaining option is DNA Profiling - also known as DNA Mapping, which shows the DNA structure and order that can be seen the same way in siblings (slightly different of course but it is still the right answer).
The source of the oxygen released into the air as a product of photosynthesis is C) Water only.
