a. The trait being shown is autosomal recessive, as both parents with normal phenotype (unaffected) have at least one copy of the recessive allele (carriers) and can pass it on to their offspring.
b. The genotype of I-2 (second individual of the second row - open square) is heterozygous carrier, as she has one normal allele (B) and one recessive allele (b), but does not express the trait (unaffected).
c. The genotype of II-3 (third individual of the second row - filled circle) is homozygous recessive, as she has inherited two copies of the recessive allele (bb) from her carrier parents and expresses the trait (affected).
d. The genotype of III-3 (third individual of the third row - open circle) is heterozygous carrier, as she has one normal allele (B) and one recessive allele (b), but does not express the trait (unaffected).
e. The genotype of III-9 (ninth individual of the third row - filled square) cannot be determined from the given information, as the phenotype of the individual is not shown, and the inheritance pattern of the trait is not linked to gender.