B. In Boravia when the economy is strong, those who might otherwise go camping tend to take vacations overseas. - Even B doesn't metion hiking people, the sales will be affected once if camping people, part of the contribution to the sales decreased.
C. The economic upturn is likely to allow Boravia’s national parks, where most of the camping and hiking is done, to receive extra funding to improve their visitor facilities. - The problem here is that C doesn't tell us whether the visitor facilitaties will include camping and hiking equipment. It is possible that the park receive funding but improve visitor facilities other than camping and hiking equipment.