
Answer:
B) 1/2
Explanation:
A sex linked trait is passed via sex chromosomes. Here the given trait is X linked recessive because female carrier is not possible for X linked dominant trait. Â
For X linked recessive trait:
Carrier female = XCXc
Affected male = XcY
Their progeny:
    XC   Xc Â
Xc  XCXc  XcXc
Y Â Â XCY Â Â XcY
Out of the sons, half will be not affected ( XCY ) and half will be affected  ( XcY )
Hence, half of the sons will express the trait.