A scientist is weighing each of 30 fishes. Their mean weight worked out is 30 gm and a standard deviation of 2 gm. Later, it was found 20.that the measuring scale was misaligned and always under reported every fish weight by 2 gm. The correct mean and standard deviation(in gm) of fishes are respectively (a) `28,4` (b) `32,2` (c) `32,4` (d) `28,2`