Which of these volcanoes is known as the "Lighthouse of the Mediterranean"?

All four answer options are volcanoes in the Mediterranean that have erupted in the recent past. Nea Kameni is in the region of Santorini, Greece, and last erupted in 1950. The other three are in Italy: Vesuvius last erupted in 1944; Etna and Stromboli are currently active.

Etna is on the Sicilian mainland, not far from Catania. Stromboli is on a small island (also called Stromboli) in the Tyrrhenian Sea, off the north coast of Sicily. The island, with a population of about 500 and an area of 12.6 square kilometres (4.9 square miles), represents the upper third of the volcano. The volcano has erupted many times and is constantly active with minor eruptions, often visible from many points on the island and from the surrounding sea, giving rise to the nickname "Lighthouse of the Mediterranean".

Stromboli has been in almost continuous eruption for more than 2,000 years. A pattern of eruption is maintained in which explosions occur at the summit craters, with mild to moderate eruptions of incandescent volcanic bombs at intervals ranging from minutes to hours. This pattern of eruption is also observed at other volcanoes worldwide. Eruptions from the summit craters typically result in a few short, mild, but energetic bursts, ranging up to a few hundred metres in height, containing ash, incandescent lava fragments, and stone blocks. Stromboli's activity is almost exclusively explosive, but lava flows do occur at times when volcanic activity is high.