What Is the Primary Reason Why People's Reaction Times Slow

Multiple Choice

What is the primary reason why people's reaction times slow down as they get older?​

A) ​Because older adults necessarily have more neurofibrillary tangles in their brains, and these tangles interfere with the cognitive processing of various tasks.
B) ​Because older adults have a decreased ability to distinguish important from unimportant information, and thus they need more time to process a given situation.
C) ​Because older adults have fewer "healthy" neurons, and thus neural messages take longer to process in the brain.
D) ​Because older adults take longer to decide that they need to respond to a given situation.