Atropical storm can turn into a hurricane when wind speed goes above 74 miles per hour wind speed is between 28-74 miles per hour an eye forms in the center of the storm an eye wall forms

The correct answer is - wind speed goes above 74 miles per hour.

The tropical storms form over the tropical seas, where there's lot of warmth and bigger water bodies. When these tropical storms reach a point where the winds surpass speed of 74 miles per hour they enter into a faze of a hurricane.

The hurricanes are characterized with a low pressure center, which is also referred to as an eye. The wind speed is very high, 74 miles per hour or more. Intense rainfall is accompanying the winds. The hurricanes are very powerful, and they cause a lot of deaths and lot of material damage.  

b. niger

explanation: