we don't want to make too many assumptions out of scope: maybe this, maybe that. If the argument doesn't mention something, then this something shouldn't be created.
同意B。 文中的前提是“Consumers planning to buy recreational equipment tend to buy higher quality, more expensive equipment when the economy is strong than when it is weak.” C提到的改良客户服务改良,并不影响这个前提,因为文中没有客户如果公共设施服务好宁愿去公共park的前提存在,所以是无关项,起干扰作用。 而B中说的经济好人们愿意去国外,直接反对这个前提。