a
Continuity equation states that the product of area of cross section and velocity remains constant
The graph of area v/s $x$ will be a straight line with positive slope
Accordingly the area of velocity v/s $x$ will be a hyperbola
Pressure and velocity are related by Bernoulli's equation as $P+\frac{\rho V^{2}}{2}=$ constant
The graph for velocity squared v/s $x$ is a second degree hyperbola; visually, it's just like a hyperbola curve
Now, the graph for a constant v/s $x$ is a horizontal straight line, thus the curve for pressure will be mirror image of the hyperbola curve about the horizontal straight line