Answer
$\therefore$ Pressure will increase (i.e $\textbf P\uparrow$).
Work Step by Step
As per the Continuity Equation,
$$A×V=Const$$
$$A∝\frac{1}{V}$$
Since a hemoglobin molecule moves from the narrow region into the wider region, the area (i.e $\textbf A\uparrow)$ increases, therefore Speed $\textbf V\downarrow$ will decrease, and pressure will increase (i.e $\textbf P\uparrow$).
