单项选择题
Wetherby Co purchased a machine on 1 July 20X7 for 
20,000. On 1 January 20X8, following a change in legislation, Wetherby Co fitted a safety guard to the machine. The safety guard cost $25,000 and has a useful life of five years with no residual value.What amount will be charged to profit or loss for the year ended 31 March 20X8 in respect of depreciation on this machine?
A．$35,000
B．$36,250
C．$37,250
D．$37,500
B．$36,250
C．$37,250
D．$37,500