Why is a soda exploding/fizzing a physical change?

The fizzing of soda is a physical change that involves the release of gaseous carbon dioxide. During fizzing of a soda, you can see bubbles of carbon dioxide in the soda rise to the top. A bottle of soda doesn't fizz when it is closed because the pressure is higher, and keeps the carbon dioxide dissolved in the liquid.

Explanation:

the correct answer is: b. pantala flavescens, because these organisms would have a high level of genetic variation due to sexual reproduction.  

because involves two organisms (parents) whose genetic material combines, sexual reproduction leads to genetic variation in new generations of offspring. the offspring is an unique organism, with new genome, more protected with the higher ability to adapted. this process is fundamental to evolution.