Figure (a) is incorrect. According to equation of continuity, i.e., av=a constant, where area of cross-section of tube is less, the velocity of liquid flow is more. So the velocity of liquid flow at a constriction of tube is more than the other portion of tube.
According to Bernoulli’s Theorem, P+

1

2

ρv2= a constant ,
i.e., where v is more, P is less and vice versa.