Final answer:
Short, hairlike structures used by eukaryotic cells for movement are called cilia. They are composed of microtubules in a 9+2 arrangement and can be found covering the surface of certain eukaryotic cells, aiding in locomotion as well as transporting mucus and debris.
Step-by-step explanation:
Short, hairlike structures used only by eukaryotic cells for movement are called cilia (option B). Cilia are short filamentous structures found on the surface of some eukaryotic cells, composed of microtubules in a 9+2 array. Unlike the singular or few long flagella that some cells have for movement, cilia are often many in number and cover the entire surface of a cell. They are primarily responsible for locomotion, moving food particles towards the mouthparts in protozoans, or sweeping mucus and debris away from the lungs in ciliated epithelial cells.