Country X` s recent stock-trading scandal should not diminish investors' confidence in the country`s stock market. For one thing, the discovery of the scandal confirms that Country X has a strong regulatory system, as the following considerations show. In any stock market, some fraudulent activity is inevitable. If a stock market is well regulated, any significant stock-trading fraud in it will very likely be discovered. This deters potential perpetrators and facilitates improvement in regulatory processes.In the argument, the portion in boldface plays which of the following roles?
【选项】It is an assumption for which no explicit support is provided and is used to support the argument` s only conclusion.