Human Reaction Time Is Usually About 0

Multiple Choice

Human reaction time is usually about 0.20 s.If your lab partner holds a ruler between your finger and thumb and releases it without warning,how far can you expect the ruler to fall before you catch it? The nearest value is:

A) 4.0 cm.
B) 9.8 cm.
C) 16 cm.
D) 20 cm.