Betty made 3/4 of the baskets she attempted in a basketball game. Which other ratio is equivalent to the number of baskets Betty made?

the complete question in the attached figure

we have that
(3/4)

case a)
6/12--------> divided by 6 both members--------> 1/2   
then
6/12 is not equivalent to 3/4

case b)
9/12--------> divided by 3 both members------> 3/4
then
9/12 is equivalent to 3/4

case c)
12/20-----> divided by 4 both members-----> 3/5
then
12/20 is not equivalent to 3/4

case d)
18/20------> divided by 2 both members-----> 9/10
then
18/20 is not equivalent to 3/4

the answer is
The other ratio equivalent is the option b) 9/12