Which of the following sentences uses commas correctly?
A.
Derrick and Mary ate lunch together yesterday but she forgot her lunch today so Derrick shared his.
B.
Derrick, and Mary ate lunch together yesterday but she forgot her lunch today, so Derrick shared his.
C.
Derrick, and Mary ate lunch together yesterday, but she forgot her lunch today, so Derrick shared his.
D.
Derrick and Mary ate lunch together yesterday, but she forgot her lunch today, so Derrick shared his.