Three Masses Are Moving Along the X-Axis

Multiple Choice

Three masses are moving along the x-axis.Their masses and velocities are ​m​₁ = ​m​ with ​v_​1 = ​v​,​m_​2 = 2​m with v₂ = 2v,and m₃ = 3m with v₃ = -3v ​(the minus sign indicating this velocity is in the negative x-direction) .The three masses collide and stick together in a completely inelastic collision.What is the resultant velocity of the combined mass?

A) 0,since their combined momentum is zero.
B) -2v/3
C) 14v/3
D) -v