Given:     and  
prove:   slope of    × slope of    = -1
statementsreasons1.  
      is similar to  given2.property of similar triangles3.  slope of  
      slope of  definition of slope4.  slope of    slope of  multiplying the slopes5.  slope of    slope of  substitution property of equality6.  slope of    slope of    = -1simplifying the right side
the table shows the proof of the relationship between the slopes of two perpendicular lines.  what is the missing statement in  step 2?
a. 

b. 

c. 

d.