12. There are 28 students whose last names begin with the letters G, H, J, or K. Information about
the probability of randomly selecting one of these students is listed below.

• probability of selecting a student whose last name begins with G: 1/7

•probability of selecting a student whose last name begins with G or H: 5/14

How many of these students have a last name that begins with H?
A. 4
B. 5
C. 6
D. 7