Explanation:

Bordeaux mixture, a fungicide used to control downy mildew and other fungal diseases, especially on grapevines, was discovered by Pierre-Marie-Alexis Millardet in 1885 in France. He observed that grapevines sprayed with a mixture of copper sulfate and lime to deter theft were also resistant to downy mildew. The mixture is prepared by combining copper(II) sulfate ($CuSO_4$) and calcium hydroxide ($Ca(OH)_2$, hydrated lime) in water. Options A, B, and C are incorrect; these individuals are not credited with the discovery of Bordeaux mixture.