When does plants start to photosynthesis

During photosynthesis, a plant translates , water and light into . I assume the carbon is further used for the growing process. I wonder how the plant grows before the time where photosynthesis is possible, i.e. before there are even leaves, in which photosynthesis occurs.

chert is a sedimentary rock composed of microcrystalline or cryptocrystalline silica. with this little bit of information, you can come to the conclusion that your answer is c.  

explanation: