[单选题]
At what rate is the human bo vacee.m9sg)3dy radiatin 3,it,r 9eya 4uthx7 -fnkao93qtcxr:g energy when it is at $33 \; ^{\circ}C$? Take the body surface area to be $1.4 \; m^{2}$, and approximate the body as a blackbody.
A. $600 \; W$
B. $700 \; W$
C. $800 \; W$
D. $900 \; W$