The correct option is
D Grana
Photosystem II is the first link in the chain of photosynthesis. It captures photons and uses the energy to extract electrons from water molecules. First, when electrons are removed water molecules are broken into oxygen gas which bubbles away, and hydrogen ions, which are used to power ATP synthesis. Photosystem II is located in the thylakoids and stacks of thylakoids is known as grana.
So the correct option is 'Grana'.