What was one significant action taken in response to the diamond market fluctuations in the 1930s?

The significant action taken in response to the diamond market fluctuations in the 1930s was the closure of De Beers mines. This response was a strategic move to manage and stabilize the diamond market during a time of economic instability and decreased demand. By closing the mines, De Beers aimed to reduce the supply of diamonds in the market, which would help maintain higher prices for the diamonds that were still available. This action demonstrated the company's influence over diamond supply and its intent to protect its interests in a challenging economic environment. Other options, such as increasing mining operations or shutting down all diamond trading, would not have effectively addressed the oversupply and declining prices experienced during this period. Thus, closing the mines was a focused strategy aimed at restoring market stability.