The equation, S = (cl, b, r, p, t...) was first formulated by:

Correct option is B

The correct answer is (B) Jenny

Explanation:
• Hans Jenny, a Swiss-born American pedologist, published the famous equation of soil formation in his book "Factors of Soil Formation" (1941).
• The equation is: $S = f(cl, o, r, p, t, ...)$
• Here, S = Soil, cl = climate, o = organisms (biosphere/biota), r = relief (topography), p = parent material, and t = time.
• This state-factor equation suggests that soil is a function of these five independent variables.
• Jenny's work revolutionized pedology by providing a quantitative framework to study soil development.

Information Booster:
• V.V. Dokuchaiev (Option A) is considered the father of modern soil science; he first suggested that soil is a natural body formed by the interaction of factors, but Jenny formalized it into a mathematical function.
• When one factor is studied while others are held constant, it is called a "climosequence" (climate), "lithosequence" (parent material), or "chronosequence" (time).

Additional Knowledge:
• Dokuchaiev (Option A): He proposed that Soil = f(Climate, Organisms, Parent Material, Relief, Time) in late 19th century Russia.
• Hilgard (Option C): Known for his work on soil chemistry and the relationship between soil and climate in the USA.
• Whitney (Option D): Milton Whitney was a pioneer in soil survey and physical properties of soil in the US Bureau of Soils.