The correct option is D Thylakoid membrane
Photosynthesis is an anabolic process happening in green plants during which plant body synthesizes its own food material by taking carbon dioxide from atmosphere and water from the soil in presence of sunlight. It proceeds in the sequence of light phase and dark phase. The reactions that take place during the light phase are known as light reactions. It is thought to be responsible for the formation of high-energy chemical intermediates, ATP and NADPH. It includes light absorption, water splitting and release of oxygen. Proteins and pigments (chlorophyll and carotenoids) that function in the photochemical events of photosynthesis, i.e. trapping the light energy and synthesis of ATP and NADPH are embedded in the thylakoid membrane. So, light reaction during photosynthesis takes place in the thylakoid membrane.