Answer:
b. 3
Explanation:
Dominant genes are represented by capital letters (such as the "O" used to show that the obesity gene is dominant) and phenotypically expressed as heterozygosis (Ot) or homozygosis (OO). These genes are those that determine a hereditary trait even when in single dose genotypes. That is, they determine their character even in the absence of their dominant allele.
Recessive genes are represented by lowercase letters (such as the "t" used to show that the thinness gene is recessive) where phenotypes are expressed only in homozygosis (tt). Thus, only the individual who presents tt genes, among the options given in the question, will not present obesity.
Gilligan represents the only person who does not have the "O" allele, his alleles are "tt", so Gilligan will not be obese. However, Ginger, who is "OO", Mary Ann, who is "Ot" and Thurston, who is "tO", have the dominant allele responsible for obesity, so from the options given, we can say that 3 individuals have the highest probability to be obese.