Final answer:
Option C is answer. Philosophical skepticism relies on doubt, questioning the certainty and reliability of knowledge, and this is most evident in arguments for global skepticism and localized forms.
Step-by-step explanation:
Arguments for skepticism strongly rely on the notion of doubt. Skepticism, in philosophical discourse, arises from doubts about the reliability of our knowledge. When skeptics argue, they focus on the possibility that our beliefs might not be justifiable to the level of certainty that we can claim to know them. For instance, the global skeptic doubts the possibility of any knowledge, targeting the lack of certainty in our beliefs. In considering localized forms of skepticism, such as moral skepticism, the challenge is to justify normative claims in the face of doubt. Hence, skepticism entails an ongoing inquiry and critical examination of beliefs, where the skeptical argument leverages doubt as a tool to question the possibility of achieving certain knowledge.
If we have doubt, we are not certain. Skepticism questions the certainty and reliability of our knowledge, suggesting that it is better to suspend belief than to rely on dubitable products of reason. By questioning the reliability of our knowledge, skepticism challenges our claims to certainty.