Which of the following is not a way that plants can obtain nitrogen?                                                                                                     

The way that plants cannot obtain nitrogen is through absorption through photosynthesis.

Photosynthesis is the process by which plants convert light energy into chemical energy, but it does not involve the absorption of nitrogen.

Plants can obtain nitrogen through absorption from the soil, where nitrogen is present in the form of nitrates and ammonium ions. Plants can also obtain nitrogen through fixation from the air, where certain bacteria in the soil or in symbiotic relationships with plants convert atmospheric nitrogen into a usable form. In addition, plants can form symbiotic relationships with bacteria that provide them with nitrogen in exchange for carbohydrates.