The correct answer is: B. decreases with increase in speed.
Reaction time is the time it takes for a person to respond to a stimulus. It is affected by a number of factors, including age, gender, and health. However, it is also affected by the speed at which a person is traveling. When a person is traveling at a higher speed, they have less time to react to a hazard. This is because the distance that a person travels in a given amount of time increases with speed. For example, if a person is traveling at 30 miles per hour, they will travel 100 feet in 2.7 seconds. If they are traveling at 60 miles per hour, they will travel 200 feet in 2.7 seconds. This means that they have half as much time to react to a hazard when they are traveling at 60 miles per hour than when they are traveling at 30 miles per hour.
There are a number of things that drivers can do to improve their reaction time. One is to be aware of their surroundings and to anticipate potential hazards. Another is to practice driving at different speeds so that they become accustomed to the different reaction times required. Finally, drivers should always be prepared to stop in an emergency. This means keeping their eyes on the road and their hands on the wheel at all times.
Here is a brief explanation of each option:
- Option A: increases with increase in speed. This is incorrect because reaction time decreases with increase in speed.
- Option B: decreases with increase in speed. This is the correct answer.
- Option C: is same for all speeds. This is incorrect because reaction time is not the same for all speeds. It decreases with increase in speed.
- Option D: none of the above. This is incorrect because option B is the correct answer.