Which of the following sentences is written correctly?
A. Tom notices when Heather enters a room, because she's usually in a great mood and has a great smile.

В.Tom notices when Heather enters a room because she's usually in a great mood and has a great smile.

C. Tom notice when Heather enters a room, because she's usually in a great mood, and has a great smile.

D. Tom noticed when Heather enters a room because shes usually in a great mood and has a great smile.