The democratic style of parenting

a. brings about lower academic performance than other parenting styles

b. brings about higher levels of high-risk behavior than other parenting styles

c. has proven to be very effective in some families.

d. none of the above.

The Democratic style of parenting takes in consideration of all family members. Most children do better academically in this setting than those brought up with other parenting styles. So, I believe the answer will be C, has proven to be effective in some families. I reached this because in all my research it says the kids do better academically, so it effective in some families. If that isn't the answer your school asks for, then it is none of the above. 

B is the answer I think