Final answer:
The theorist known for the "law of three stages" and "social physics" is Auguste Comte, not listed among the options provided. None of the options (Herbert Spencer, Karl Marx, Emile Durkheim, Max Weber) directly correspond to Comte's contributions.
Step-by-step explanation:
The theorist best known for their evolutionary theory, or "law of three stages," and who conceptualized a new social science called "social physics" is Auguste Comte. Although not listed as an option in your question, Comte is the correct answer. He introduced the idea that societies evolve through three stages: theological, metaphysical, and scientific (or positive). Comte is also recognized for reintroducing the term sociology and is considered the father of sociology. Unfortunately, the options provided in the question do not include Comte, so it may be a mistake on the part of the question maker. If forced to choose from the given options, none directly match the achievements of the "law of three stages" and "social physics" which are attributed to Comte.