This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Genetics, Subject name: Pathology
True statement regarding chromosomes 
Select and explain. 
A. In females both X chromosomes are activated, B. Klinefelter syndrome results due to an extra Y chromosome in males, C. Germinal cells contain 23 chromosomes, D. Turner syndrome results due to an extra X chromosome in females
B: Klinefelter syndrome results due to an extra Y chromosome in males
Answer: B: Klinefelter syndrome results due to an extra Y chromosome in males 
Explanation: Ans. (b) Klinefelter syndrome results due to an extra Y chromosome in males(Ref: Robbins 9th/pg 166; 8th/pg 165)a. False: Only one of the X chromosomes is genetically active, the other X of either maternal or paternal origin undergoes heteropyknosisand is rendered inactive called Barr body, so females have one activated chromosomeb. True: Klinefelter syndrome is best defined as male hypogonadism that occurs when there are two or more X chromosomes and one or more Y chromosomesc. False: Germs cells have haploid set of 23 chromosomesd. False: Turners is due to missing X chr.