Identify which option in each of the following groups is punctuated correctly.

a) Please send the memo to: Boston, New York City, and Los Angeles.
b) Please send the memo to Boston, New York City, and Los Angeles.
c) Please send the memo to; Boston, New York City, and Los Angeles.

a) I practiced my presentation for three hours this afternoon, it is on management strategies.
b) I practiced my presentation for three hours this afternoon; it is on management strategies.
c) I practiced my presentation for three hours; I thought we were closing the Baker account today.