Supply chains have become more vulnerable to crises because: Single sourcing can make companies more vulnerable to supply chain interruptions when a natural disaster strikes in the region the supplier is located. Lean supply chains are less able to withstand shocks and disruptions because of the lesser amount of inventory on hand. "Because of global outsourcing, supply chains have more vulnerability points which make them susceptible to interruptions of deliveries." All of the above items make supply chains more vulnerable to a crisis. Only b and c make supply chains more vulnerable to a crisis