suppose that you enter into a short futures contract to sell july silver for 17.20 per ounce. the size of the contract is 5000 ounces. the initial upfront margin is 4000 and matinence margin requires the account has at least 3000 of margin thereafter. what change in the futures price will lead to a margin call

a decline of .20 per ounce

an increse of .20 per ounce

a decline of .60 per ounce

an increse of .60 per ounce