We can go through each point:
A) The total amount of people surveyed can be find by adding all the categories result:
A total of 84 people were surveyed.
B) The number of students surveyed can be find by adding only the categories for students:
50 students were surveyed.
C) We can see how many parents prefer to watch TV in the category that intersects "parents" and "watch TV". It has a frequency of 9, so there are 9 parents that prefer to watch TV.
D) Explained in point C.
E) We can compare the percentages by adding the categories "Read a book" and "Watch TV" separately, dividing them by the total number of people surveyed and then compare:
It seems there is no significant difference between the categories.
Answer: The statements that are true are A and C.