To solve this problem, we need to identify the genetic disorder characterized by overall masculine development, gynecomastia, and sterility. Let's analyze each option:$\newline \bullet$Turner's syndrome:$\newline$ - Turner's syndrome is a condition affecting females, where one of the X chromosomes is missing or partially missing.$\newline$ - It is characterized by short stature, delayed puberty, infertility, and certain physical features, but not by masculine development or gynecomastia.$\newline$ - Therefore, this option is incorrect.$\newline \bullet$Klinefelter's syndrome:$\newline$ - Klinefelter's syndrome is a genetic condition affecting males, where they have an extra X chromosome (XXY).$\newline$ - It is characterized by overall masculine development, gynecomastia (breast development in males), and sterility.$\newline$ - This matches the description given in the question.$\newline \bullet$Edward syndrome:$\newline$ - Edward syndrome, also known as Trisomy 18, is a genetic disorder caused by the presence of an extra chromosome 18.$\newline$ - It is characterized by severe developmental delays and physical abnormalities, but not by the features described in the question.$\newline$ - Therefore, this option is incorrect.$\newline \bullet$Down's syndrome:$\newline$ - Down's syndrome, or Trisomy 21, is a genetic disorder caused by the presence of an extra chromosome 21.$\newline$ - It is characterized by intellectual disability and distinct facial features, but not by masculine development or gynecomastia.$\newline$ - Therefore, this option is incorrect.$\newline$Based on the analysis, the correct answer is Klinefelter's syndrome, which corresponds to Option 2.