If Sheffield Ltd has a margin of safety of $101000, which of the following statement is correct a) Sales can increase by $101000 before Sheffield has an operating loss. b) Fixed costs can increase by $101000 before Sheffield has an operating loss. c) Sales can decrease by $50500, and fixed costs can increase by $40400 before Sheffield has an operating loss. d) Sales can increase by $50500, and fixed costs can decrease by $50500 before Sheffield has an operating loss