About 95% of earthquakes in South Africa are a result of mining. Although, there is a height restriction for buildings in Welkom due to the risks of quakes. Hospital exceeds this limit but is specially designed to resist tremors. Overall there are few problems to solve relating to earthquakes in South Africa which is to closely monitor activities of miners and ensure that they comply with best practices.
You didn't place any of your following answers, which makes it difficult for people to help. What do you think it is? Out of the options that you have.