The right answer is A (which represents this picture).
The first phase of photosynthesis, called the light phase, requires the illumination of the sheet. This photochemical phase corresponds to the capture of light energy by light-absorbing pigments and its conversion into chemical energy in the form of ATP. In this reaction, the photosensitive pigments ("chlorophyll b", carotene and xanthophylls) absorb and then channel the light energy to the "chlorophyll a" whose electrons are brought to a higher energy potential. In this excited state, the electrons of chlorophyll are derived to a system that extracts and stores their energy for later use in the synthesis of sugars. The result of this electron transfer is the splitting of the water molecules to give hydrogen (H) and oxygen (O) atoms. Oxygen escapes in O2 gas form into the atmosphere through open stomata. This whole sequence is done in a fraction of a second.
During the second phase of photosynthesis (improperly called "dark phase"), the CO2 of the atmosphere unites with a particular sugar (ribulose diphosphate). The product is cut in two equal parts, the hydrogen from the light reaction is added, and the resulting molecule (PGAL glyceraldehyde phosphate) is used for the manufacture of small base units to build more elaborate molecules. Although the CO2 fixation reaction is slower than the light reaction, millions of PGAL molecules are synthesized within minutes after the light enters the cells of the leaf.
The first products resulting from this metabolic process are represented by various types of sugars, including glucose and fructose (both have the formula C6H12O6 but with a different molecular structure). They can combine to form sucrose (C12H22O12), the common sugar used at the table and obtained from sugar cane or beet.
