Two shaded square regions, including their edges, are shown above in the xy -plane and are labeled I and II, respectively. $$S$$ is the set of all possible slopes of line segments $$PQ$$, where point $$P$$ is in region I and point $$Q$$ is in region II.
Quantity A
The greatest member of set $$S$$
Quantity B
$$\frac{4}{3}$$