Concept:NPA is the acronym for the official Nigerian body in charge of seaports and related water traffic.
Explanation:NPA is an abbreviation that stands for Nigerian Ports Authority.
It is a government-owned organisation established in 1955 to develop and manage the country's seaports.
Its duties include providing facilities for water traffic movement, such as berths and cargo handling equipment.
It also controls pollution in rivers and ports to keep the waterways safe and operational.
Comparing the acronym with the options, option A says "Police" instead of "Ports", which is incorrect.
Option C changes "Nigerian" to "National", so it is also wrong.
Option D has both "National" and "Police", making it the least accurate expansion.
Therefore, the only correct expansion of NPA is Nigerian Ports Authority.
Answer:B. Nigerian Ports Authority