1Many animals, including some insects, use visual clues to find their way. 2For example, the female digger wasp lays eggs in a burrow in the soil. 3She then flies off to capture her prey, which she stores in the burrow to feed her offspring when they hatch. 4The famous animal-behavior scientist Niko Tinbergen studied the cues used by the female to relocate her burrow. 5While the female was inside, Tinbergen surrounded the nest with pine cones. 6When the wasp emerged, she flew around the nest before departing. 7While she was gone, Tinbergen moved the cones about a foot away. 8The returning wasp still sought her nest within the ring of cones. 9Although the nest was in plain sight nearby, she was unable to locate it because the visual landmarks on which she relied had been shifted.

10Birds may also use landmarks, such as rivers and seashores, to find their way. 11Several species migrate at night or over large expanses of ocean, using the position of the sun or stars to tell direction. 12Many species seem to have genetically programmed information about the direction of the sun at various times of day, and also possess a biological clock that measures off a roughly twenty-four-hour day. 13Other birds have the remarkable ability to “read” the night sky. 14Indigo buntings, for example, seem to have a built-in star map that enables them to find which direction is north, during spring migration, by looking at the stars.

Question 1 – In sentence 4, the word cues means
A - visual clues.
B - movements.
C - suggestions.
D - lines.