Please answer the following question: I'm taking a test and have to guess the right answer to the question after the article. Article: A British dog-lover has invented a high-tech way of feeding his pet by Twitter( ,). Computer expert Nat Morris ,30, has designed a system to give his pet a "tweet treat" by sending him a Twitter message. His dog Toby gets some delicious dog biscuits from a computer-controlled food machine whenever Nat sends a message to "@ feedtoby". Nat often works away from home and isn't always able to feed Toby by hand. But his new invention allows Nat to feed his dog from anywhere in the world. Nat said, "Toby ly loves it. At first he didn't know what was going on. Now he sits underneath the machine, wagging his tail and waiting for the food to drop." Nat fills the food machine with small pieces of dog biscuits, but not too many in case four-year-old Toby gets too many messages. And Nat has even equipped his house with an online camera so he can see Toby enjoying the food at his home. But one problem is that friends and family have been so amazed with the "tweet treat" machine that they have started sending tweets to Toby too. So Nat has had to restrict feeding time to make sure Toby doesn't turn into Tubby. "People have been sending him tweets at all hours of the day, so I had to limit it to between 9a.m. and 9 p.m. . I'm thinking of doing an updated one which can measure his weight before he is fed, just to make sure he's not putting on too much puppy fat," explained Nat. How Nat's Twitter Feeder works: When a message is sent to @ feedtoby, it is received by a mini -computer that is linked to the feed machine. When the mini-computer receives the message, a bell rings and Toby comes running over and sits in front of the feeding machine. Next, the machine's motor pulls open a trap door which releases a serving of food. The doggy biscuits then drop into Toby's food bowl. Finally a digital camera takes a photo of him and sends it back to Nat on Twitter -- so he knows Toby has been fed. Question: Why has Nat decided to limit the feeding machine's operating time? Options: A: He doesn't want Toby to get too fat. B: He fears the machine will run out of food. C: He wants his friends to stop feeding Toby. D: He doesn't want Toby to be woken up at night.
A:
A