Was it literally dark in the "dark ages? " i have heard it said that there was a volcanic eruption that darkened the sky for many years.? any truth to that? (i know it preceded the "age of enlightenment" etc.)

Which statement best explains the relationship between an area's geography and the temperature of its surface water? areas at low altitudes have the warmest water because they receive the most direct sunlight. areas at low altitudes have the warmest water because they have the least change in temperature throughout the year. areas at high latitudes have the warmest water because their days are the longest. areas at high latitudes have the warmest water because they have the longest seasons.