For the Following Issue, Discuss Which Source You'd Trust More

Essay

For the following issue, discuss which source you'd trust more, and give at least one reason why. You may want to add to or otherwise modify our list of sources. And do keep in mind that we are glad our livelihoods do not depend on a general consensus on our rankings.
Issue: Do mountain bicycles cause ecological damage when ridden on hiking trails?
a. an environmental scientist at the Harvard School of Public Health
b. the chair of the Sierra Club task force for determining club policy on the wilderness use of mountain bicycles
c. a spokesperson for a bicycle manufacturer
d. a park ranger from a state park where mountain bicycles have been permitted on hiking trails
e. a representative of the Washington Mountain Bike Riders' Association