Which identifies the cause of each type of mutation

1. DNA fails to copy accurately
Most of the mutations that we think matter to evolution are "naturally-occurring." For example, when a cell divides, it makes a copy of its DNA — and sometimes the copy is not quite perfect. That small difference from the original DNA sequence is a mutation.

2. External influences can create mutations
Mutations can also be caused by exposure to specific chemicals or radiation. These agents cause the DNA to break down. This is not necessarily unnatural — even in the most isolated and pristine environments, DNA breaks down. Nevertheless, when the cell repairs the DNA, it might not do a perfect job of the repair. So the cell would end up with DNA slightly different than the original DNA and hence, a mutation.

it's the release of intestinal gas, which forms as a result of digesting food. when partially digested carbs reach the colon, bacteria convert part of that food into hydrogen and carbon dioxide gasses. you cant stop the stink, its a gas that comes naturally.

explanation:

i think a) betsy can donate only blood to mark is correct because, mark and betsy have the same blood type. whereas nobody else has b+ blood so betsy can't donate to them.