An experiment was designed to study the potential impact of alcohol consumption on emotional stability. a specification of the variables and procedures used to measure emotional stability illustratesa. the independent variable. b. an operational definition. c. the double-blind procedure. d. random assignment. e. the dependent variable.

b. an Operational Definition

Explanation:

An operational definition is the expression of conceptual model (or procedural statement)  used to define the terms of a method required to determine the essence of an object or  an occurrence and its characteristics including period, volume, spatial expansion,  chemical properties.

answer; ///i believe the correct answer is (b) the writing of the ancients who lived in india after the indus valley inhabitants died out;