Storms that form in the tropics are given names when: a. they reach tropical storm strength. b. they become fully developed hurricanes. c. they approach to within 250 miles of land. d. rotation becomes visible on a satellite potograph.

Storms that form in the tropics are given names when  a. they reach tropical storm strength .

Explanation :

Formation of storms a generally over the tropical ocean waters , and , when the storm is formed in the eastern pacific , it is called as a hurricane .

And ,

It is called as a cyclone , in the Indian Ocean .

This type of weather pattern , in the North Pacific Ocean is called a Typhoon .

Generally storm are given names in tropics when they reach tropical storm strength .