It really depends, think of it as 2 light bulbs in each parent. if both light bulbs in both parents are switched on that means their genes that they inherited are only able to have brown eyed babies, although if just 1 of the 4 light bulbs are not on it allows the baby to have blue eyes.
There is loads of choices so I could not really tell what the best one is. Although I wouldn't know because I'm a guy so I cant really tell what the best one is. I did look that question up and loads showed up on the right of my screen.
Sorry
Answer:
Try to use less cars because they cause pollution bike instead, cars release gases which cause pollution, I hope this helps