Correct Answer: Debacle

Solution : The correct choice is the fourth option .

Calamity refers to a disastrous or catastrophic event that causes widespread damage, distress, or adversity. On the other hand, debacle relates to a sudden and significant failure or disaster. The similarities between "calamity" and "debacle" lie in their association with disastrous occurrences.

The meanings of the other words are:

• Embark : This means to start or begin a journey or endeavour.
• Debauchery : This means excessive indulgence in sensual pleasures or immoral activities.
• Debar : This means to exclude or prevent someone from participating.

Therefore, the right answer is debacle .