The finding of the study mentioned in this passage

单项选择题

A study by Dr. David Lewis from The University of Sussex, who coined the term " road rage," found that motorists face a hidden mental health impact from the stresses of driving, while bus travel can produce long-term health benefits.
For the experiment, the heart rate and EDR (Electro-Dermal Response)of 30 commuters was measured when taking similar journeys by car and bus．The findings reveal a vast difference in EDR, a form of biophysical measurement that indicates mental stress. The EDR results suggested that taking the car produced significantly more stress than taking the bus, which was 33% less stressful.
"EDR can be a hidden stress—it’s not as visible as intensely nervous driving or audible as road rage. This type of stress can have long-term physiological and emotional implications," said Dr.Lewis, who finds three key factors that increase the stresses of driving a car.
Driving in heavy traffic—especially against a deadline—requires a high level of attention. This requires the brain to work especially hard processing a myriad of incoming information and making, often split-second, decisions．
Congestion and delays can raise blood pressure and physical tension which may manifest itself as " road rage, "having serious long-term health consequences and causing drivers sometimes to take reckless and foolish decisions. Driving in congested traffic now outweighs any previous benefits car-driving once gave．
A sense of frustration of" wasting one’s life" behind the wheel of the car, unable to do anything more productive than casual conversations or listening to the radio. On a bus it is possible to fill the time more profitably by doing some work or reading.
He also notes that highly trained, professional bus drivers are skilled in negotiating the challenges of the road,and the relief of trusting someone else to be in charge of the journey is a key part of what makes taking the bus less stressful.
He encourages people to get out of their cars and on to the bus for trips where it makes sense—such as shopping in town or heading to a restaurant—so that you don’t need to battle traffic or find parking．Switching simple journeys can help achieve the goal of taking a billion Car journeys off the road．All it will take is everyone shifting around a trip a month.

The finding of the study mentioned in this passage is that ______.

A.cars cause more traffic accidents than buses
B.driving a car is more stressful than taking a bus
C.high blood pressure is harmful to human’s health
D.Car driving is accompanied by many distractions