I need help ;(

A. Chloroplast

Explanation:

Chloroplast, often known as the kitchen of the cell, is where photosynthetic reactions combining light energy from the Sun into chemical energy [Glucose] that is stored as food. They contain a Green Color Pigment called 'Chlorophyll' that initiates the process, but Chlorophyll isn't an organelle, in fact, it is one of the elements of Chloroplasts. Similarly, Thylakoids are membrane-bound elements inside Chloroplast that aid in photosynthesis. While Mitochondria, [Power Houses Of Cells] generate energy for various processes in cells through ATP-Generations.

all matter is made up of atoms

in any element all atoms are the same

elements in a compound are always in a constant ratio: apex