What is meant by an argument from sign?

An argument from sign refers to a reasoning process that identifies an effect and infers its cause. This type of argument allows one to observe the presence of a specific signal or indicator, which suggests the existence of something else that is not directly observable. For instance, if you see dark clouds in the sky, you might conclude that rain is likely on the way. In this case, the dark clouds serve as a sign, leading you to deduce the probable cause—rain—based on that observable effect. This reasoning method is valuable in various contexts, including scientific inquiry, forensic analysis, and everyday decision-making. The option that mentions reasoning from an effect back to a cause correctly captures this relationship and illustrates the essence of a sign argument.