In order to "see" something smaller than about 200 nm, an electron microscope can be used. an electron would have to be traveling at m/s in order to have a de broglie wavelength of 200 nm.

3640 m/s The de Broglie wavelength of a particle is expressed by the equation: λ = h/p where λ = wavelength h = Planck constant p = momentum so let's solve for momentum and the substitute the known values and calculate: λ = h/p λp = h p = h/λ p = 6.62607004x10^-34 Js/2x10^-7 m p = 6.62607004x10^-34 kg*m^2/s^2 * s/2x10^-7 m p =3.31303502x10^-27 kg*m/s Now momentum is defined as mass times velocity. And the mass of an electron is 9.10938356×10^-31 kg. So p = mv p/m = v 3.31303502x10^-27 kg*m/s / 9.10938356×10^-31 kg = v 3.63694754774384x10^3 m/s = v Rounding to 3 significant figures gives 3.64x10^3 m/s or 3640 m/s. That velocity is low enough that we don't need to worry about relativistic effects.

Where are the options ?

The answer is water molecules are split.cellular respiration and photosynthesis are complement  reactions to each other. these are reverse reactions. in cellular respiration glucose and oxygen yield water and carbon dioxide. so, when respiration begins,  glucose molecules are split. in the opposite reaction - in photosynthesis, carbon dioxide and water yield glucose and oxygen. thus,  when respiration begins, water molecules are split.