An atom with how many electrons in its shell is most stable

An atom that holds eight electrons in it's shell is stable. This means it can't react with other elements because the shell is already full. These elements are called Noble Gases and are on the last column of the Periodic Table.

Ithink option a is correct because you cannot donate a different blood group than yours because it won't match.option a says betsy can donate to mark. they have the same blood group so donation can happen.