【正确答案】 B

【答案解析】[听力原文]
Communication is the transfer of information. Animals often communicate among their own species. Sometimes they even try to communicate with other species. Most communication is done through body language. Sounds and smells are also means to communicate. The most obvious body language you see between animals is threatening postures. Cats will bend their back to make themselves appear bigger. Each species has postures that warn others in their species that the animal is ready to fight. Other species also recognize these signs. A pack of wolves will communicate among each other about the tactics they are using when surrounding prey. Animals also communicate through sounds and smells. Elephants trumpet in a very low tone that humans cannot hear but can feel. This sound can be felt by the sensitive skin of an elephant's feet and trunk up to 5 miles or 7.5 kilometers away. Spider monkeys have certain calls to indicate a predator is in the area. Smell is used to communicate breeding times and to indicate territorial boundaries. Animals often mark their territories with smelly urine. Odors also indicate when a female is sexually receptive. Although humans do most of their communication through the use of words and obvious gestures, much can be learned from observing the subtle communications of animals. Body language, the tone of a person's voice and body odors can provide considerable amount of information about the person's intentions, mood and even health.

What is the most obvious body language for animals?