Normal Males (XY)and Klinefelter Males (XXY)both Possess Only One Active

Normal males (XY) and Klinefelter males (XXY) both possess only one active X chromosome.Nonetheless there are clearly phenotypic differences between the two.What is the MOST reasonable explanation as to why such differences exist?

A) The Y chromosome has higher gene expression levels when two X chromosomes are present compared to one X.
B) The Y chromosome has lower gene expression levels when two X chromosomes are present compared to one X.
C) Some genes remain active on inactive X chromosomes, so XXY males would produce higher expression levels for these genes compared to XY males.
D) XXY males exhibit a higher rate of problems during mitotic divisions than XY males.
E) XXY males don't have a copy of the SRY gene.