Two Canadian Couples, Julia and Anna and Mark and Laura

Two Canadian couples, Julia and Anna and Mark and Laura, want to adopt a child. Who, on average has a better chance of adoption in Canada, and why?

A) Mark and Laura, because mixed-sex couples are more likely to be matched to children than same-sex couples.
B) Julia and Anna, because there are on average twice as many same-sex than mixed-sex couples waiting to adopt children in Canada.
C) Julia and Anna, because female-only couples are considered safer for adoptive children than mixed-sex or male-only couples.
D) Mark and Laura, because adoption by same-sex couples is illegal in Canada.