Given the question: Read the following article and select the best answer. Article: TOKYO, JAPAN--What do you do when you see a cockroach ? Do you hit it with a newspaper? Do you step on it? When researchers at Tokyo University see a cockroach, they take the remote control and make the cockroach turn around, run left or right, or go forward. These scientists are changing the cockroaches into robots. Each cockroach has a very small pack that has in it a microprocessor .Then researchers can send signals from the remote control to the pack. The signals control the movements of the cockroaches. Why does anyone want to control a cockroach? "Insects can do many things that people can't," says Isao Shimoyama, head of robot research at Tokyo University. In a few years, he says, these robot insects will carry very small cameras. They will be able to move through earthquake rubble to look for people or move under doors to find information about someone. This may seem strange, but the Japanese government thinks the research is very important. The government is giving the scientists $ 5 million for this research. First, the researchers breed hundreds of cockroaches. They use only the American cockroach because it is bigger and stronger than other cockroaches. Then they choose the best cockroaches and remove their wings and antennae . They put small packs where the antennae were. The packs weigh about three grams, or about two times the weight of the cockroaches themselves. "Cockroaches are very strong," says Ralph Holzer, who is a researcher at Tokyo University. "They can lift 20 times their own weight. " With a remote control, the scientists send signals to the packs. When a cockroach gets the signal, it moves. The problem is that the cockroaches don't always move in the right direction. Question: What problem do the rcscarchcrs meet with? - The cockroachcs sometimes clon;t move. - The cockroachcs sometimes move in ihc wrong direction. - The cockroachcs arc too big to move through earthquake rubble. - The cockroachcs can only lift 20 times their own weight.
The answer is:
The cockroachcs sometimes move in ihc wrong direction.