Task: Text Categorization
Input (English): Question: Determines the isotype change of the immunoglobulin heavy chain: 
 Options:  <0> The receptor of cell B. <1> The CD40 molecule and the cytokines. <2> IgM or IgD of the lymphocyte membrane. <3> Age. <4> The location of the lymphocyte within the germinal center.
Output (English): biology