The correct answer is C) The presence of icebergs. The presence of icebergs is not an indication that pack ice may be nearby. Icebergs are large chunks of ice that have broken off from glaciers or ice shelves and float freely in open water, while pack ice refers to smaller pieces of ice that are still connected and floating together. The presence of icebergs suggests that the water is sufficiently deep to allow them to float, rather than indicating the presence of shallow pack ice. In contrast, sighting a walrus (A), observing an ice blink (B), and the absence of wave motion (D) can all be signs that pack ice may be present in the vicinity.