(V)The Fridge-door effect - Why do we instantly forget?Have you ever had the experience of walking to the fridge, opening the door and forgetting whatyou wanted to take? This is usually called “the fridge-door effect”. A similar situation happenswhen you are going to say something but can’t remember the words that you need. This is the famous“tip-of-the-tongue phenomenon”. Both the fridge-door effect and tip-of-the-tongue phenomenonare deterioration of memory performance. It happens more often for people as they get into their40’s and 50’s.People easily forget the information that they don’t use within 18 to 30 seconds. If theinformation is used by the brain in some other way, it can last for up to several minutes. If we keepusing it, it can turn into a long-term memory and will become closer to being remembered for alltime.The fridge-door effect happens because of the missing of short-term-memory information.On the way from your room to the fridge, you are probably paying attention to something else, andthe original focus is then removed from short-term memory. In this case, when you get to thefridge, you just can’t remember what you were going to take. The tip-of-the-tongue phenomenonhappens because of a slowdown of memory performance, similar to the situation of an old CPU in acomputer. When information processing slows down, longer time will be needed for the brain tofind the needed information.Besides growing old, lack of sleeping, taking medicine, overworking and being nervous can alllead to deterioration of memory performance. Exercising is especially helpful for keeping ormaking memory performance better. It increases blood flow to the brain and helps memoryperformance, both in short and long terms. (From: Hanlin) 
48.Which one has the closest meaning as “deterioration” in paragraph one?
(A) speed up
(B) forgetting
(C) becoming worse
(D) losing