Which one of the following is a filter feeder?

Oysters are filter feeders because they obtain nutrients by straining suspended organic matter and plankton from the water through their specialized gill structures. While Pelicans might be a tempting choice due to their large pouch, they are actually predators that swallow whole prey rather than filtering microscopic particles. The core concept tested is the classification of organisms based on their ecological feeding mechanisms and functional roles in an ecosystem.