Answer: The serious tension between the government of Egypt and Ethiopia is due to the construction of:
b) an Ethiopian dam to produce hydroelectric power.
Explanation: This Ethiopian dam is known as the Grand Ethiopian Renaissance Dam (GERD), this is a gravity dam which has been under construction from 2011. This dam is been done on the river Nile, Egypt who also use the river Nile as a downstream basin for fresh water is objecting to effect of the dam in their country.