For Christmas, Josh and Cybil, Who Are Brother and Sister

For Christmas, Josh and Cybil, who are brother and sister, each recently received 25 iTunes music downloads and 10 movie passes. Josh's marginal rate of substitution of music downloads for movie passes is 1/4, while Cybil's marginal rate of substitution of music downloads for movie passes is 2. For a Pareto improvement over the original allocation, Josh gives Cybil _____ music download(s) for _____ of her movie passes.

A) 1; 3
B) 3; 1
C) 8; 1
D) 1; 4