Identify the sentence that is punctuated correctly.
A. In December, 2013 I visited my aunt for Christmas in Allentown, Pennsylvania, for the first time in 20 years B. In December 2013, I visited my aunt for Christmas in Allentown, Pennsylvania for the first time in 20 years
C. In December 2013 I visited my aunt for Christmas in Allentown, Pennsylvania, for the first time in 20 years
D. In December, 2013, I visited my aunt for Christmas in Allentown, Pennsylvania, for the first time in 20 years