Task: Text Categorization
Input (English): Question: A neutral gene mutation: 
 Options:  <0> Change a coding codon by another synonym without altering the amino acid sequence of the protein. <1> A coding codon changes with a different one and the protein is functionally different. <2> It generates a non-functional protein. <3> It changes the amino acid sequence of the protein without altering its function. <4> Suppresses the effect of a previous mutation.
Output (English): biology