Cell organelles found only in plants are

The correct option is Plastids.

Let us understand why this option is correct by comparing plant and animal cell structures:
1. Ribosomes are found in both plant and animal cells, as they are essential for protein synthesis.
2. Mitochondria are the powerhouses of the cell and are present in both plant and animal cells to generate energy through cellular respiration.
3. Golgi complex (or Golgi apparatus) is involved in modifying, sorting, and packaging proteins and lipids, and is found in both plant and animal cells.
4. Plastids (such as chloroplasts, chromoplasts, and leucoplasts) are double-membrane-bound organelles responsible for photosynthesis and storage of food. These organelles are unique to plant cells (and some algae) and are completely absent in animal cells.