Wow, I booted that one, didn't I? (That's what happens when I try to type and watch the football game at the same time :o) Very sorry, Alterescu. ROA is
\frac{\text{Net Income}}{\text{Total Assets}} .
There...much better.
Now on to the subject of the question. Your thinking is on track--ROA is an indication of how many dollars of net profit you're generating per dollar of assets employed. All other things constant, increasing your ROA is certainly a positive move.
But I think the question is asking for some possible reasons why a company's ROA might be favorable vis-a-vis its industry average, while its ROS is significantly lagging its peers.
For example, here's one possibility: A company that's significantly less capital-intensive (fewer long-term assets), but more labor-intensive (higher current expenses in its cost structure) than the industry average might exhibit such ROA and ROS stats as those in your problem.
Or for a different twist: Company A's assets might predominantly be a lot of antiquated, fully depreciated plant and equipment (badly in need of upgrades and replacements). The fact that they're fully depreciated would tend to push the company's ROA metric northward (and also an illustration of why you gotta look under ROA's hood and see what's driving the numbers, and not just take it at face value).
Just a couple of thoughts you can run with. Good luck with your project!