Finding relative price from budget constraint on indifference curves, economics homework help

Graph with pizza on the x-axis and apples are on the y-axis. There is a straight line budget constraint sloping down and 3 upward concave indifference curves labelled U1, U2 and U3. U1 is closest to the origin (lowest utility) and intersects the budget constraint at point W. U2 is tangent to the budget constraint at pizza = 6 and apples = 30. This is point X. U2 also has a point Y labelled which lies beyond the budget constraint. U3 is the indifference curve furthest from the origin. It does not touch the budget constraint. It has a point Z labelled at pizza = 6 and apples = 50.

FYI – All the point are supposed to lie on the indifference curves for these questions even if they appear a touch off.

Based on the budget constraint and 3 indifference curves shown here we know that:

A. If pizzas cost $1 then apples must cost $0.20
B. If pizzas cost $1 then apples must cost $4
C. If pizzas cost $1 then apples must cost $0.25
D. If pizzas cost $1 then apples must cost $5
E. If pizzas cost $1 then apples must cost $1

How do I find the relative price?

I tried finding the differences from the slopes but got different slopes.

Please explain