One hour before John started walking from P to Q, a distance

One hour before John started walking from P to Q, a distance of 18 miles, Ann had started walking along the same road from Q to P. Ann walked at a constant speed of 3 miles per hour and John at 2 miles per hour. How many miles had Ann walked when they met?

A. 6 miles
B. 8,4 miles
C. 9 miles
D. 9,6 miles
E. 12 miles