A zookeeper, Aaron, tells you the following: 
"Our biggest problem is keeping track of animal feeding. Knowing which animals have been fed is a recurring problem. We end up with double feeding a lot. And that causes a couple of problems. First, we're spending too much on food each month. But the other problem is that some of the animals are getting, uh, fat."

Following domain-driven design practices, which of the following would be an appropriate response by a developer?

Based on the conversation snippet above, which of the following is an early candidate to be a use case/user story?

The conversation continues:

Zookeeper Charburi: "Yes, the double feeding is an issue. But also ordering the correct food is a challenge. Sometimes it's easy. We can order a month's supply of wombat food pretty easily. Just give our supplier a call. Well, OK, there was that one time last year where we couldn't get any in, and the wombats became ornery little guys. Anyway, some of the animals only eat living plants. We have to monitor them to make sure they haven't been chewed to the root. But that means we have to walk and check on on those cages. Some of those habitats are on the far side of the park. Could you just install sensors or something?"

Based on what you have heard so far, which of the following is a good candidate to be an actor?