DUBAI, March 7 (Reuters) - Saudi Arabia slashed its official selling price (OSP) for April for all its crude grades to all destinations, after OPEC's oil supply cut pact with Russia fell apart on Friday, sending oil into a tailspin. State oil giant Saudi Aramco has set its Arab light crude oil to Asia for April at a discount of $3.10 to the Oman/Dubai average, down $6 a barrel from March, the company said in a statement late on Saturday. It cut the April OSP of its Arab light crude oil to the United States to a discount of $3.75 per barrel versus ASCI, down $7 a barrel from March. Aramco lowered its OSP for Arab light crude oil to Northwestern Europe to a discount of $10.25 per barrel to Ice Brent, down $8 a barrel. A three-year pact between OPEC and Russia ended in acrimony on Friday after Moscow refused to support deeper oil cuts to cope with the outbreak of coronavirus and OPEC responded by removing all limits on its own production. Oil prices plunged 10% as the development revived fears of a 2014 price crash, when Saudi Arabia and Russia fought for market share with U.S. shale oil producers, which have never participated in output-limiting pacts. Saudi Arabia is the de facto leader of the Organization of the Petroleum Exporting Countries and the world's biggest oil exporter.

Q Can you use economic tools like total cost, variable cost, marginal cost, fixed cost to explain the above scenario. Also please explain the events in the case using graphs if possible