If proceedings are brought against Dire Straits Pty Ltd to have the company wound up based on insolvency which of the following would potentially compel the court to presume insolvency:

a. a letter from Dire Straits Pty Ltd's suppliers notifying cancellation of trade credit, and requesting cash on delivery

b. a recent failure to produce audited financial reports

c. unpaid employees wages for the month of May

d. failure to comply with a statutory demand served by the company's electricity provider under section 459E.