Tom and philip were given the graph of a linear function and asked to find the slope. tom says that the slope is 1/2

while philip says that the slope is 2.

which reason correctly justifies tom's answer?

a) slope is found by
run
rise
so if you pick two points on the graph you have to count 1 unit to the right and then 2 units up.

b) slope is found by
run
rise
so if you pick two points on the graph you have to count 2 units to the left and then 1 unit down.

c) slope is found by
run
rise
so if you pick two points on the graph you have to count 1 unit to the right and then 2 units down.

d) slope is found by
rise
run
so if you pick two points on the graph then you have to count 1 unit up and then 2 units to the right.