What type of chemical reaction is taking place 6CO2 6H2O C6H12O6 6O2?

Photosynthesis:

6CO2 (carbon dioxide) + 6H2O (water) --> C6H12O6 (glucose) + 6O2 (oxygen)

or

2n CO2 (carbon dioxide) + 2n H2O (water) --> 2 (CH2O)n + n O2 (oxygen) + 2n (electron donor)