please help! asap! brainliest to the right answer!
The orbital radii of four planets in our solar system are shown in the following table.

Orbital Radii
Planet Orbital Radii (AU)
W 5.2
X 0.72
Y 0.37
Z 19.1

Which planets are likely to be inner planets?

Select one:
a. W and X
b. X and Y
c. Y and Z
d. X and Z