The question is designed to test the understanding of the term 'ingenuity' as used in the passage. The correct answer is 'C. The cleverness in designing tools' because the passage discusses how people have devised cunning tools, which indicates clever design. Option A is incorrect because it refers to the ability to perform tasks, not the cleverness in designing. Option B is incorrect because it refers to the science of robotics, which is a result of ingenuity, not the definition of it. Option D is incorrect because it refers to the process of mechanizing work, which is a consequence of ingenuity, not the definition.