Refer to the Table

Refer to the table.Researchers grew seedlings with phosphate fertilizer, arbuscular mycorrhizae, or both, and then weighed the seedlings after six months. Which explanation best describes why the weight of the seedlings did not increase when the amount of phosphate was doubled in the absence of mycorrhizae?

A) The amount of phosphate added was over and above the absorptive capacity of the plant roots.
B) Without mycorrhizae, no phosphate was available for uptake by the roots.
C) The additional phosphate is converted to unusable form in the soil.
D) Other plants compete for the added phosphate at higher concentrations.
E) There was experimental error in that plot of plants.