What is the best way an animal could adapt if the weather started turning cold and stayed cold forever?

Which of the following is an example of this type of co-evolution

Agene pool: a) is the collection of all the alleles found in a single species b) is the collection of all the alleles found in a single population c) is the collection of all the chromosomes found in a single population d) is the collection of genes in a species that allow the individuals to swim

Which is the correct formula for photosynthesis