Which of the Following Statements Best Describes the Region of the Immunoglobulin

Multiple Choice

Which of the following statements best describes the region of the immunoglobulin molecule that is responsible for specific binding to the antigen?

A) The constant regions of the heavy and light chains in the Fab fragment interact to form a specific antigen-combining site.
B) The variable regions of the light and heavy chains in the Fab fragment interact to form a specific antigen-combining site.
C) The constant regions of the heavy and light chains in the Fc fragment interact to form a specific antigen-combining site.
D) The variable regions of the light and heavy chains in the Fc fragment interact to form a specific antigen-combining site.