Choose the correct answer from the list below. Not all of the answers will be used.
-The methyl group donor _______________ is the product of the first step of methionine degradation.

A)hyperammonemia
B)aminotransferases
C)methionine
D)S-adenosylmethionine
E)glutamate dehydrogenase
F)oxaloacetate
G)biopterin
H)glutamate
I)hippurate
J)urea
K)dehydratase
L)dioxygenases
M)ammonia disorder