Which of the following is punctuated correctly?
a. Several things bring me memories of my mother; roses, snow, amethysts, and piano music.
b. Several things that bring me memories of my mother are: roses, snow, amethysts, and piano music.
c. Several things that bring me memories of my mother are; roses, snow, amethysts, and piano music.
d. Several things bring me memories of my mother: roses, snow, amethysts, and piano music.