Which two of the following common CFTR mutations are the most likely to result from Cas9 cleavage followed by non-homologous end joining?
A. G542X (class I mutation: nonsense mutation)
B. 3272-26A>G (class V mutation changing an A nucleotide at a splice junction to a G, thereby interfering with mRNA splicing)
C. G551D (class III mutation: missense mutation changing a glycine codon to an aspartic acid codon)
D. R334W (class IV mutation: missense mutation changing an arginine codon to a tryptophan codon)
E. F508del (class II mutation: deletion of a phenylalanine codon)