To do a proper comparison, convert all measures to the same unit, in this case, to feet (It is not necessary to convert A, C and E, they are already given in feet).
B
[tex]15yd\cdot\frac{3ft}{1yd}=45ft[/tex]D
[tex]600in\cdot\frac{1ft}{12in}=50ft[/tex]F
[tex]540in\cdot\frac{1ft}{12in}=45ft[/tex]B, C and F are equal.