4. (a), (b), (c)의 각 네모 안에서 문맥에 맞는 낱말로 가장 적절한 것은?
in the past, many public-sector recreation providers allowed people free access, or charged for permits to control the season for different recreational activities. however, governments are finding that funding to maintain sites and facilities, to cope with increased demand on the landscape, is becoming difficult to maintain. opportunities to (a)[charge / support] visitors for appropriate services to help offset these costs are being considered as one solution. this is a sensitive matter, as free access for all people to the outdoors is a much cherished right. there is also an additional (b)[solution / dilemma] for public agencies where recreation facilities are already provided from public money, and it could be argued that the taxpayer is being charged twice. thus, care is needed by public bodies to ensure that charges are only made for services that are clearly (c)[additional / central] to the provision of free access.

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