Seafloor spreading causes an oceanic plate to collide with a continental plate. if it were to go through the whole tectonic cycle, number the steps that would follow.

If you're going to ask a question, at least provide the steps or possible answers that you are provided with so that others can help you. Luckily, I know the exact question you are trying to solve. 
The order the steps go in is:
  The oceanic plate would subduct under the continental plate into the asthenosphere. 
From the intense heat and pressure within the mantle, the crust of the oceanic plate would mix with the rock of the mantle. 
Mantle convection would cause magma to rise up through divergent boundaries.

The entire process is mentioned in  step-wise below-

Firstly, two plates moves opposite to each other, due to this the crust gradually become thin and subsequently rises up.On continuous thinning of the crust, at one point, the magma will come out to the surface producing a small rift.Rifting continuously takes place and results in a rift valley,and slowly after millions of years will form an ocean.Then, the two diverging plate will collide with another oceanic or continental plate, in which the more denser oceanic crust will get subducted beneath the less denser one.This suducted plate, at much greater depth undergoes partial melting and slowly makes its way up to the crust.This magma on further pushing towards the surface, initiates sea floor spreading, thus repeating the entire cycle.