Concept:Petrochemical industries locate close to their main raw material, which is crude oil.
Explanation:Rivers State is part of the Niger Delta region of Nigeria.
The Niger Delta is the country’s main oil-producing area.
It contains the majority of Nigeria’s crude oil and natural gas deposits.
Petrochemical industries use crude oil and natural gas as raw materials to produce chemicals, plastics, fertilisers, and fuels.
To reduce transportation costs and secure a constant supply of these raw materials, such industries are sited near the source, which is why they are concentrated in Rivers State.
Favourable soil and climate are not major location factors for heavy industries.
Coal deposit is not the relevant resource, because the petrochemical industry depends on crude oil.
Therefore, the presence of crude oil is the decisive reason for locating petrochemical industries in Rivers State.
Answer:Crude oil deposit (Option C).