Which one doesn't belong?

A worksheet with five rows of images, each containing four items and one item that doesn't belong. The top row shows a stroller, a paintbrush, a paint palette, and a toy car. The second row has a pencil, a notebook, a leaf, and a book. The third row includes a basket, a fish, a fish, and a fish. The fourth row shows a fish, a fish, a fish, and a fish. The fifth row has a fish, a fish, a fish, and a fish.