Correct Response: B. “Will an incandescent lamp last longer if it is left on continuously or rapidly turned on and off?” is the only question that seeks to establish a relationship between a dependent variable (duration of the lamp) and an independent variable (switched on and off or run continuously) that can be verified by an experiment. A relationship between the independent and dependent variables can readily be derived from this question, and the relationship can be tested using experimental methods. None of the other answer choices (A, C, or D) are concerned with the relationship between an independent and a dependent variable, so no hypothesis is implied by any of them.
