On October $1,$ a company borrowed $$60,000$ from Eighth National Bank on a $1-$year, $7\%$ note. If the company's fiscal year ends on December $31,$ a year$-$end adjusting entry is required to increase

a$.$ notes payable by $$1,050.$

b$.$ interest expense by $$4,200.$

c$.$ prepaid interest by $$3,150.$

d$.$ interest payable by $$1,050.$