It is known that for right-handed people, the dominant (right) hand tends to be stronger. For left-handed people who live in a world designed for right-handed people, the same may not be true. To test this, muscle strength was measured on the right and left hands of a random sample of 15 left-handed men and differences (left - right) were calculated. The alternative hypothesis was one-sided (left hand stronger). This is an example of:

A. A two-sample t-test.
B. A one-sided test.
C. A crossover test.
D. A pooled t-test.
E. A paired t-test.