Correct Answer & Explanation
Option D
• The sentence refers to a failure to make payments. 'Default' means failure to fulfill an obligation, especially to repay a loan.
• 'Defray' means to pay expenses.
• 'Defile' means to make something dirty or impure.
• 'Deficient' means lacking.
• 'Defer' means to postpone.
• Thus, 'Default' is the most suitable word.