Buying drinks

This task is about reading information from graphs.
illustration: selection of different fizzy drinks
Four friends each bought a bottle of drink. The graph below shows the relationship between the cost of each bottle they bought and the volume in each bottle.
 
Cost and volume of different fizzy drinks
cost - volume graph of different bottles of fizzy drink

Question

a)  i)  Whose bottle held the least drink?

    • Courtenay

    • Marley

    • Grace

    • Troy

Question

ii)  Whose bottle cost the least?

    • Courtenay

    • Marley

    • Grace

    • Troy

Question

b)  i)  Who paid the least amount of money for the most amount of drink?

    • Courtenay

    • Marley

    • Grace

    • Troy

ii) Explain your answer