Answer:
The correct answer is option B. has a defective allele and normal phenotype.
Explanation:
Genetic carrier or the hereditary carrier is an organism or a person that has a recessive allele for a particular trait or character (generally mutation) but does not exhibit the trait or any character related to the trait.
The carriers are normal in the sex-linked characters in comparison to the autosomal traits. Females are generally the carrier for sex-linked characters and carry the allele to the next generation.
Thus, the correct answer is option B. has a defective allele and normal.
 
        
             
        
        
        
Maybe D but at the same time it could be A
        
             
        
        
        
Histone deacetylase is responsible for removing the acetyl group from the histone 3 lysine 9 residue. Remember that deacetylation is one step in converting euchromatin to heterochromatin. Because euchromatin is transcriptionally active (transcriptional machinery is able to reach gene of interest), and blocking histone deacetylase activity would result in an the DNA remaining as euchromatin, we would expect to see an increase in transcriptional activity.
So there’s your answer: An increase in transcriptional activity.
        
             
        
        
        
Toxicology is the study of poison on living things