Z plc provides a single service to its customers. An analysis of its budget for the year ending 31 December 2002 shows that in period 4, when the budgeted activity was 5220 service units with a sales value of £42 each, the margin of safety was 19.575 per cent. The budgeted contribution to sales ratio of the service is 40 per cent. Budgeted fixed costsin period 4 were nearest to

a £1700

b £71 000

c £88 000

d £176 000