I believe the answer I the third option
During these initial reactions, water is used and oxygen is released. The energy from sunlight is converted into a small amount of ATP and an energy carrier called NADPH. Together with carbon dioxide, these are used to make glucose (sugar) through a process called the Calvin Cycle.
Multi cellular organisms are composed of many cells whereas unicellular organisms are composed of single cell. Multicellularity is indeed a progressive attribute of evolution where cells form tissue which forms organ and then organ system and finally an organism. Both multi cellular and unicellular organisms has advantages and disadvantages of their own. One of the main disadvantage of multi cellular organisms is that due to such a complex composition and functioning they require a large amount of energy for their maintenance and survival. Different organs and system require a huge amount of energy when it comes to comparison with unicellular organisms. A large amount of energy is also wasted in all these life processes. Though multi cellular organisms can survive in a variety of environmental conditions but then also their survival is difficult than any unicellular organism.
