Earlobes may either be joined to the cheek or free-standing (unattached). A single gene controls this feature. The allele for attached earlobes is recessive. The diagram illustrates the inheritance pattern of attached earlobes in one family. Which two individuals must be heterozygous for earlobe attachment?
- A1 and 7
- B3 and 4
- C5 and 8
- D6 and 9