At its usual speed of \(40 \,\text{km/h,}\) the bus covers its journey on schedule. But when its speed reduces to \(35\,\text{km/h,}\) it takes \(15\) more minutes than scheduled time. Find the distance of the journey.
A. \(50 \,\text{km\)
B. \(60 \,\text{km\)
C. \(70 \,\text{km\)
D. \(75 \,\text{km\)
E. \(80 \,\text{km\)
OA C