c
(c)If the liquid is incompressible then mass of liquid entering through left end, should be equal to mass of liquid coming out from the right end.
\(\therefore \;M = {m_1} + {m_2}\) ==> \(A{v_1} = A{v_2} + 1.5A\,.\,v\)
==> \(A \times 3 = A \times 1.5 + 1.5A\,.\,v\) ==> \(v = 1\;m/s\)