Directions for Quantitative Comparison Questions: Some of the following questions give you two quantities, one in Column A and one in Column B, Compare the two quantities and choose one of the following answer choices: A．if the quantity in Column A is greater; B．if the quantity in column B is greater; C．if the two quantities are equal; D．if you cannot determine the relationship based on the given information

A． an attack on poorly constructed sleep research studies
B． a critique of recent scientific studies on REM-sleep
C． a warning against getting too little sleep
D． an analogy between human and non-human sleep processes
E． an overview of specific processes that may occur during different stages of sleep in humans