The dark reaction of photosynthesis occurs in:

Explanation

The dark reaction of photosynthesis, also known as the Calvin cycle, takes place in the stroma of the chloroplast. The stroma contains the necessary enzymes for carbon dioxide fixation, where carbon dioxide is converted into glucose using ATP and NADPH from the light reactions. The thylakoids and grana are involved in the light-dependent reactions, where light energy is captured to produce ATP and NADPH, but they are not sites of the dark reaction. The cytoplasm also does not take part in this process, as it lies outside the chloroplast. Therefore, the stroma is the correct location for the dark reaction of photosynthesis.