[单选题]
Oxygen molecules are 16 times more mas+ehvs/25kjnxpq xo kc/)12xj sive than hydrogen mo n52kbs3ly5ya rbq9peb; e*4 olecules. At a given temo5 5yabebe*pkn y;9sbqr 43l 2perature, how do their average molecular speeds compare? The oxygen molecules are moving
A. 4 times faster.
B. at 1/4 the speed.
C. 16 times faster.
D. at 1/16 the speed.
