Answer:
b. eustatic changes
Step-by-step explanation:
The changes in the sea-levels are caused by several factors. The basic factor is the global change in the temperatures, or rather the global warming. With the temperatures being higher across the globe, lot of ice from the ice sheets and glaciers melts, thus increasing the water in the oceans. As this happens, the water gradually becomes warmer and warmer because of the higher temperatures, and the warmer water has bigger volume, thus resulting in further increase of the sea-levels. The eustatic changes can not be taken as factor that cause the sea-level changes because they are what represents the sea-level changes, not what influence them.