Which one of the following scientists used the nutrient culture solution in hydroponic cultures?

Soilless culture helps in knowing:

Carefully observe the following figure.
$(a)$ Name the technique shown in the figure and the scientist who demonstrated this technique for the first time.
$(b)$ Name at least three plants for which this technique can be employed for their commercial production.
$(c)$ What is the significance of the aerating tube and feeding funnel in this setup?

What is hydroponics?

Hydroponics is $............$

Hydroponics is a system of growing plants in