The answer would be the number 2) no amino acid change (silent mutation)
*When we examine the original sequence, we can notice that the ACGGCAUUC-AAG-GCUACGUACCCUUCUAUC mutated into ACGGCAUUC-AAA-GCUACGUACCCUUCUAUC.
*These codons AAG and AAA refer to LYSINE. Therefore, even if there is a change when the guanine (G) becomes adenine (A) in the mutated version, there is no change in the amino acid.