we know that

A relationship between two variables, x, and y, represent a direct variation if it can be expressed in the form y/x=k or y=kx

Part 1)

Find the value of k for each data in the table

a) For the point(8,28)

k=y/x

k=28/8=3.5

b) For the point(16,56)

k=y/x

k=56/16=3.5

c) For the point(20,70)

k=y/x

k=70/20=3.5

therefore

the value of k is equal for the three points in the data set

so

the data represent a direct variation

the equation is equal to

y=3.5x

therefore

the answer Part 1) is the option C

yes; y=3.5x

Part 2)

Find the value of k for each data in the table

a) For the point(40,32)

k=y/x

k=32/40=0.8

b) For the point(28,16)

k=y/x

k=16/28=0.57

c) For the point(16,12)

k=y/x

k=12/16=0.75

therefore

the value of k is different for the three points in the data set

so

the data not represent a direct variation

therefore

the answer Part 2) is the option A

no;y does not vary directly with x