Much in the same way that animals kill each other for life to continue. The key is to do it responsibly, like the other animals do.
False. There's no correlation between an animal's behavior and "being responsible" when searching for food. Hunting for animals is an optimization problem in risk assessment. They have hundreds of thousands of years of evolution to support that claim. Hunting is risky (get an injury while chasing game, and you're probably not going to live), it takes a lot of energy to chase down game (animals don't have the benefit of rifles or other "tools" to hunt with), and the reward is only realized if they're successful.
People, on the other hand, have the luxury of not needing to go hunt wild game to eat. We can just go to the grocery store to get it. We have to think of being responsible, since hunting for food (in the same sense that an animal has to hunt) is not a necessary condition for our continued survival.