For every 1/2 mile that Ria runs, she walks 3/4 miles. What unit rate gives the number of miles Ria runs for every mile she walks?

A) 2 miles run to 3 miles walk
B) 2/3 miles run to 1-mile walk
C) 3 miles walk to 2 miles run
D) 3/2 miles walk to 1-mile run