Answer:
(only ii right?)
Since we have the total number is 360° and our section is 72°, we know that the percentage of students who choose the cinema should be the number that we have divided to the total amount and then multiply the result by 100 ( it's fine if you write 100%, but when you actually calculate it, it's only 100, not 100%):
(72/360) . 100 = 20%