Plz answer i really need lots of points i'm begging

Lets consider the dominant allele to be represented by T and the recessive allele to be represented by t.

The punnet square can hence be completes as:

        T         t

T     TT      Tt

t       Tt       tt

The blanks can be filled as:

1: t

2: T

3: Tt

4: T

5: Tt

6: t

7: TT

8: Tt

9: tt

10:Tt

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.