Read the text and fill in the blank with the correct relative pronoun: "System InitiativesThe global, regional and industry challenges facing the world are the result of many “systems” – from global systems influence the environment and natural resource security, to the economic systems that create inequality, to the regional systems that determine the fortunes of nations, to the industry systems that determine the effectiveness of supply and demand. To enable our constituents to make sustained positive change, we work with them to understand and influence the entirety of the system that affects the challenges and opportunities they are trying to address. We do this through a series of System Initiatives, described below."