Q: Read the following article and answer the question. Article: Can dogs help with OCD? You might watch and laugh when your dog chases its tail because it looks cute. But did you know that, even though it might appear like a fun game, it could mean your pet is sick? Researchers have found that if a dog runs after its tail, chases cars and barks at flies that are not there, it may have obsessive compulsive disorder (OCD, ). In fact, OCD is even more common among humans. The symptoms are varied: some people check and recheck the locks before they go out; others are extremely afraid of germs and have to wash their hands many times a day. English soccer star David Beckham, for example, cannot stand odd numbers of items in his fridge. So if he has three cans of drink he will throw one out, according to his wife Victoria. Hoping to better understand OCD in humans, a team of scientists from the University of Helsinki, Finland, studied 368 dogs, including those that chase their tail for several hours daily or a few times a month, according to Sciencedaily.com. They also examined dogs that had never chased their tails. Scientists took the dogs' blood sample and asked their owners some questions about their pets' daily life. Findings showed that among all kinds of dogs, bull terriers and German shepherds were likely to chase their tails, which led scientists to believe that genes can cause OCD. Diet also plays a part. It was found that dogs that eat food with certain vitamins and minerals chased their tails less. "Interestingly, there are indications that vitamins and minerals are helpful in human OCD treatment," said researcher Katriina Tiira. Moreover, tail-chasing is often found among dogs that were separated from their mothers too early or ones that didn't receive enough care. They are also more likely to turn out to be shyer and more afraid of loud noises at a young age. The study can help us understand the causes of OCD in humans. "Dogs share the same environment with humans, and large animals are physiologically close to humans," said Hannes Lohi, leader... Question: According to the study, OCD _ . Answer:

Choose your answer from: (1). will help dogs to become braver (2). shows similar symptoms in dogs and humans (3). is more common among dogs than among humans (4). can be eased with the help of certain vitamins and minerals
A:
(4).