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?

(N/A) The technique shown is Hydroponics,which was first demonstrated by Julius Von Sachs in $1860$.
$(b)$ Three plants for which this technique can be employed for commercial production are:
$(i)$ Solanum lycopersicum (Tomato)
$(ii)$ Hibiscus esculentus (Okra)
$(iii)$ Solanum melongena (Brinjal)
$(c)$ The significance of the components is as follows:
- Aerating tube: It provides air (oxygen) to the nutrient solution,which is essential for the respiration and optimum growth of roots.
- Feeding funnel: It is used to add water and nutrient salts to the solution as per the requirement of the plant.