The following transactions are the only ones made during the first 4 days that a futures contract trades. DAY TRANSACTION 1 A long 30, B short 30 2 A long 55, C short 55 3 A long 45, D short 45 4 C long 45, A sells 20, B sells 25 What is the open interest on these days? 30, 85, 130, 105 30, 85, 130, 110 30, 55, 45, 50 30, 85, 130, 115