The Following Is a Short Segment of an MRNA Molecule

The following is a short segment of an mRNA molecule. The polypeptide it codes for is also shown:
5 ' AUGGUGCUGAAG 3 ': methionine-valine-leucine-lysine
A mutation in the DNA occurs so that the fourth base (counting from the 5 ' end) in the messenger RNA now reads A rather than G. What sequence of peptides will the mRNA now code for? (You do not need a copy of the genetic code to answer the question.)
A) methionine-lysine-leucine-lysine
B) methionine-leucine-leucine-lysine
C) methionine-valine-methionine-lysine
D) methionine-methionine-leucine-lysine