Cuase of 1999 earthquake in colombia

The area has a high seismic risk because this is where three different tectonic plates converge (Nazca, Cocos, and Pacific) it also didn’t help that the city was poorly engineered due to old age.

This area has a well known high seismic risk, due to the triple junction that occurs at the northwest corner of the South American Plate where the Nazca, Cocos, and Pacific plates converge. About 60% of the existent poorly engineered structures in Armenia collapsed, due to the high number of old structures, built without technical requirements and the lack of urban planning and land studies.

Iwould say the answer would be b