Choose the correct answer from the list below. Not all of the answers will be used.
-_______________ is/are often found to cause alternative structures in DNA replication.

A)uracil
B)DNA ligase
C)Huntington disease
D)Ames
E)xeroderma pigmentosum
F)tumor-suppressor genes
G)trinucleotide repeats
H)skin carcinoma
I)mutagen
J)direct repair
K)indirect repair
L)photolyase