The correct answer is option 'D', Ptolemy II. The Lighthouse of Alexandria, also known as the Pharos of Alexandria, was constructed during the reign of Ptolemy II, who was a king of the Ptolemaic dynasty in Egypt.

The Lighthouse of Alexandria:
The Lighthouse of Alexandria was one of the Seven Wonders of the Ancient World. It was located on the island of Pharos, near the city of Alexandria in Egypt. The lighthouse was built to guide ships entering the harbor of Alexandria and to serve as a symbol of the city's prosperity and power.

Construction and Design:
The construction of the lighthouse began around 290 BC and was completed around 280 BC. It was designed by the Greek architect Sostratus of Cnidus. The structure was built with large blocks of white limestone and rose to a height of approximately 120 meters (394 feet). It consisted of three levels: a square base, a middle section with eight sides, and a cylindrical top. At the very top, a mirror was used to reflect sunlight during the day, while a fire was lit at night to provide light to guide the ships.

Role and Importance:
The Lighthouse of Alexandria served as a crucial navigational aid for sailors and traders in the Mediterranean Sea. Its light could reportedly be seen from a distance of up to 35 miles (56 kilometers). The lighthouse was equipped with a sophisticated system of mirrors and lenses that focused and intensified the light, making it visible even during adverse weather conditions. It played a vital role in ensuring the safe navigation of ships and the economic prosperity of Alexandria.

Legacy and Destruction:
The Lighthouse of Alexandria stood for centuries as a symbol of architectural and engineering excellence. However, over time, it suffered damage from earthquakes and other natural disasters. The lighthouse was eventually completely destroyed, possibly during the 14th century, after centuries of deterioration. Today, only ruins and underwater remains of the lighthouse can be found near the location where it once stood.

Conclusion:
The Lighthouse of Alexandria, constructed during the reign of Ptolemy II, was an iconic structure that served as a navigational aid and symbol of Alexandria's power and prosperity. Its construction and design showcased the advanced architectural and engineering skills of the ancient world. And though it no longer stands today, its legacy lives on as one of the Seven Wonders of the Ancient World.