[单选题]
At what temperature is the average kineticiexs id6t f 1se:5an23nsdx-d6v;/b f energy ofap9/ mow3n u9co)ezw, ;a k/oj an atom in helium gas equal to c a93wnwom9oe,; aup)kjo z//$6.21 \times 10^{-21} \; J$?
A. $200 \; K$
B. $250 \; K$
C. $300 \; K$
D. $350 \; K$
