What is the main purpose of this passage? ''Raise the Driving Age to Eighteen!''

Without stratospheric ozone, which of the following would most likely occur? i. smog over major cities would be greatly reduced. ii. farms would produce surplus crops because of increased photosynthesis. iii. uv radiation would damage phytoplankton and reduce populations of aquatic consumers. i only ii only iii only i and ii i and iii