[单选题]
A sample of an ideal gas is slowly compressed tob3bb: w2 ry(ce2je7u f one-half its original v9dy/8/4vm rqri+w/ .ixky b uoolume with no change in temperature. What happens to+//kix uvyb 4r 9m./dywo8qri the average speed of the molecules in the sample?
A. It does not change.
B. It doubles.
C. It halves.
D. none of the above
