The correct answer is Liver. Explanation & Key Takeaways: • The kupffer's cells present in the liver are amoeboid shaped, they are attached to sinusoidal endothelial cells. Hence option 3 is correct. • The surface of kupffer's cells contains pseudopodia, lamellipodia, and microvilli. • The pseudopodia and microvilli play an important role in endocytosis. • The cytoplasm present inside the kupffer's cells contains ribosomes, centrioles, microfilaments, Golgi apparatus, and microtubules. • Kupffer cells contain a nucleus, which is indented, ovoid and they can be lobulated. • The structure and kupffer's cells' function are depending on their location in the liver. • The kupffer's cells present in the periportal region are comparatively larger and have more lysosomal enzyme and phagocytic activity. • The average life span of the kupffer's cells is around 3 - 8 days. • The primary kupffer's cells' function is to remove the foreign particles and debris, which enter the liver through the portal system.