Joseph Owes $15,000 to Carmel Enterprises,$8,500 to Vulcan Co

Joseph owes $15,000 to Carmel Enterprises,$8,500 to Vulcan Co. ,$11,000 to David and $11,500 to Sigma Enterprises.He has not been making payments on these debts for the past 20 months.Which of these creditors can force Joseph into involuntary bankruptcy?

A) Carmel Enterprises only
B) Carmel Enterprises and David only
C) Carmel Enterprises,Sigma Enterprises,David,and Vulcan Co.
D) Sigma Enterprises,David and Vulcan Co.only