Final answer:
A low pressure system of tropical origin in the Atlantic and Caribbean basin with max sustained winds of at least 39 mph is classified as a tropical storm, which is the precursor to hurricanes.
Step-by-step explanation:
A low pressure system of tropical origin in the Atlantic and Caribbean basin with max sustained winds of at least 39 mph is classified as a tropical storm. Tropical storms are the precursor to hurricanes and have wind speeds between 39 and 73 mph. Once a storm reaches sustained winds of 74 mph or higher, it is upgraded to a hurricane.