Two cyclists, k kilometres apart, and starting at the same time, would be together in r hours if they travelled in the same direction, but would pass each other in t hours if they travelled in opposite directions. The ratio of the speed of the faster cyclist to that of the slower is :

• A. $\frac{{r + t}}{{r - t}}$$
• B. $\frac{r}{{r - t}}$$
• C. $\frac{{r + t}}{r}$$
• D. $\frac{r}{t}$$