Before a researcher specified the relationship among variables he must have a (an) : A: Inventory of variables B: Inventory of propositions C: Arrangement of propositions D: Schematic diagram

Option B

Step-by-step explanation:

Before a researcher specifies the relationship among variables he must have an inventory of propositions/constructs which are mostly stated in a declarative form. These are then tested by examining the relationships between measurable variables of this constructs/propositions.