It is desired to measure parameters of 230 V/115 V, 2 kVA, single-phase transformer. The following wattmeters are available in a laboratory: W 250 V, 10 A, Low Power Factor W : 250 V, 5 A, Low Power Factor W: 150 V, 10 A, High Power Factor W4: 150 V, 5 A, High Power Factor The Wattmeters used in open circuit test and short circuit test of the transformer will respectively be (A) W and W (B) W and W4 (C) W and W (D) W2 and W3