Evelyn turned up the thermostat from 68 degrees to 70 degrees; however,she doesn't think it feels any warmer and she wants to turn it up even higher.Her roommate thinks that it is now too hot,and she wants to turn the thermostat back down.How does Evelyn's just noticeable difference compare to her roommate's

A)  Evelyn's is smaller. 
B)  Evelyn's is lower. 
C)  Evelyn's is larger. 
D)  Evelyn's is higher.

Just noticeable difference (JND) refers to the smallest amount of change in a stimulus that can be detected by a person. In this scenario, Evelyn turned up the thermostat by 2 degrees (from 68 to 70), but she couldn't notice any difference in temperature. This indicates that her JND is larger. On the other hand, her roommate wants to turn the thermostat back down, suggesting that she can detect a smaller difference in temperature. Thus, her JND is smaller than Evelyn's. Therefore, option C, which states that Evelyn's JND is larger, is the correct answer.