A Manufacturer Has Designed Athletic Footwear Which It Hopes Will $\text { 100-metre }$

A manufacturer has designed athletic footwear which it hopes will improve the performance of athletes running the $\text { 100-metre }$ sprint.It wishes to perform a hypothesis test to compare the times of athletes at the 100 metres with these shoes and with their usual shoes.

A) Two-sample t-test,since the experiment has two samples.
B) Either two-sample or paired t-test would be equally accurate.
C) Pooled t-test,since the standard deviations of the two populations are likely to be the same.
D) Paired t-test,since a natural pairing exists,and would detect differences between the population means better.
E) Not enough information is given to determine correct type of test.