Mean Sea Level

Mean sea level

A) is a consistent value yet to be determined due to the variables involved in producing the tides.
B) is at the same level along the entire North American coast.
C) is based on average tidal levels recorded hourly at a given site over a period of many years.
D) has very little variability across all ocean basins and,therefore,is treated as an absolute value.
E) is constant enabling scientist to determine a single value thereof,though there are local minor variations.