This pedigree shows the inheritance of Tay-Sachs in a family. Tay-Sachs is a recessive disorder that causes cells to be unable to break down waste products. These wastes build up in brain cells and cause damage and eventual death.

Which numbers have the genotypes of tt?

TT = normal
Tt = carrier
tt = disease

a
1, 2, 3, 4, 6, 7, 8, 9, 12, & 13
b
5, 10, 11, & 14
c
5, 6, 7, 8, & 9
d
10, 11, 12, 13, & 14