This pedigree chart tracks the inheritance of a recessive trait that is not sex-linked. based on the information in the chart, which of the following statements is true?

a. individual #11 must be homozygous for the recessive trait.
b. individuals #3 and #4 must be heterozygous for the trait.
c. individual #2 must be heterozygous dominant for the trait.
d. individual #9 must be homozygous dominant for the trait.