A.
See below for a graph
B.
The inverse of a function appears on a graph as the reflection of the function across the line y=x. This is because the inverse relation is effectively the same relation with the variables x and y swapped. Here, the graphs of f(x) and g(x) are mirror images of each other across the line y=x, so we can see they are inverse functions.
The same technology allows us to graph y=f(g(x)) and y=g(f(x)). Both are graphs of y=x, as expected.