Choose the Correct Answer from the List Below

Choose the correct answer from the list below. Not all of the answers will be used.
-____________: Compact regions that may be connected by a flexible segment of polypeptide chain.

A) amino
B) water
C) protons
D) DNA
E) secondary structure
F) tertiary structure
G) Ramachandran
H) RNA
I) domain
J) cystine
K) proline
L) Sanger
M) D amino acids
N) cysteine