What is the difference between adaptation and natural selection

Adaptation is both an evolutionary process and a product of natural selection: adaptation is a process of evolution in which traits are modified by natural selection; an adaptation is a phenotypic trait moulded by natural selection. In both cases the evolution is driven by natural selection.

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.