Answer:
b and c are parallel lines
Explanation:
Parallel lines have equal slopes
The product of the slopes of perpendicular lines = - 1
Calculate the slopes m of the lines using the slope formula
m =

with (x₁, y₁ ) = (6, 7 ) and (x₂, y₂ ) = (1, 1 )
=
=
=

Repeat with (x₁, y₁ ) = (7, 10 ) and (x₂, y₂ ) = (2, 4 )
=
=
=

Since slope are equal then line b and line c are parallel lines