The correct answer is C) Red lights on the LDB (left descending bank) and green lights on the RDB (right descending bank). This lighting configuration indicates a navigational channel, but not one passing under a fixed bridge. Instead, this arrangement of red and green lights marks the edges of a navigational channel, typically on rivers or other waterways. The red and green lights help mariners identify the proper course and navigate safely through the channel. The other answer choices, such as two green lights in a range or a fixed red light on each pier, are not the correct lighting combinations for a navigational channel passing under a fixed bridge.