The ones you will check is A, C, E, F, G.
This is because al organisms compete with each other for food and habitats, so they need to compete for survival.
However, animals do not mutate if they are struggling to survive. A mutagen is something that causes a mutation, and mutagens are usually external chemicals, not exactly a situation that an animal is in.
Some organisms do indeed have phenoyupes that beat competitors as a phenotype is a set of observable characteristics. If a specific animal has camouflaging skin as its observable traits, while another does not, this will beat the competitor with their phenotypes.
Thirdly, all organisms undergo natural selection, which is why this is not ticked. If plants did not undergo natural selection foods like bananas and apples as well as carrots would not be anywhere near it is today. Think about how little seeds there are in a banana, they used to be ginormous, but they changed as the humans did not eat the ones that had to many seeds, and let it spread those seeds.
Natural selection does indeed occur to this day, as many organisms continue to undergo genetic mutations to live and survive.
Phenotypes found in the most succesful members would become prevalent in later generations as those are the characteristics that makes the species survive, and it will pass on its traits to others.
Finally, if there is a decrease in food, the population will change as not as many animals can live.