The coco river is a natural border between nicaragua and which other country

Coco River, Spanish Río Coco, river in southern Honduras and northern Nicaragua, rising west of the town of San Marcos de Colón, in southern Honduras, near the Honduras-Nicaragua border. The Coco flows generally eastward into Nicaragua, then turns northward near Mount Kilambé.

The answer is 1-plate movement along fault lines

Answergranulation;