TOEFL Listening: TPO-TOEFL阅读TPO - G_Z49974K12S935UN$

Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information A. When an animal is signaling in an area with green-to- yellow lighting conditions, its signal will not be visible if the background is brightly lit B. In the lowest levels of the forest, an animal s signals are not easily see unless there is a yellowish or greenish background C. In the green-to-yellow lighting conditions at the lowest levels of the forest, only signals that are themselves green or yellow will be bright enough to be seen in most areas. D. Although green and yellow would be the brightest colors near the forest floor, these colors would make poor signals whenever the forest background was also in the green-to-yellow range