Answer:
In coastal areas, strong winds and powerful waves break off soft or grainy rocks from hardier rocks. Too much weathering occurs, it might break off parts of the cliff and be dangerous to humans, or animals.
Rain has acid in it which could eat up the cliff.
Explanation:
The correct answer is the Black Market.
The Black Market refers to the informal (and sometimes formal) system of trading of illegal goods by merchants and dealers of products such a weapons, drugs, and good that have been banned by countries. This can also apply to informal marketplaces in countries with sanctions placed upon them get goods that formal treaties are blocking the people from accessing.