Biology · Genetics

A specific gene 'X' exhibits genomic imprinting, causing its inactivation depending on parental origin. A loss-of-function mutation in this gene leads to an adult-onset genetic disorder. Individuals carrying the mutant allele are traced across generations. Shaded individuals express the clinical disorder, while dotted individuals carry the mutant allele without showing the disease in an unshaded state. Consider the following genetic statements: A. Gene X is maternally imprinted (inactivated when inherited from the mother). B. An individual who inherits the mutated allele from the silencing parent will carry an imprinted allele and remain unaffected. C. If two carriers (III.4 and III.5) have a child, the probability that the offspring inherits at least one copy of the mutant allele via standard Mendelian transmission is 0.75. D. If individuals III.4 and III.5 have a child, the probability that it will display the disorder is 0.75. Which one of the following options represents the combination of all correct statements?