A Researcher Is Studying the Rate of Consumption of CO₂ $\rarr$

Multiple Choice

A researcher is studying the rate of consumption of CO₂ by some plants in a sealed container. If the plants are the major use and source of gases is by the following photosynthesis reaction, what does the researcher need to be concerned about as the reaction proceeds?
6 CO_2(g) + 6 H₂O_(l) $\rarr$ C₆H₁₂O_6(s) + 6 O_2(g)

A) the build up of total pressure
B) the loss of the partial pressure of reactants
C) the loss of total pressure
D) the loss of partial pressure of products
E) keeping the plant in a dark room