Final answer:
A major obstacle to economic growth in developing countries is (d) the low supply of saving, which impacts investment and development. In financial markets, a rise in supply can lead to a decline in interest rates due to increased capital availability.
Step-by-step explanation:
A major obstacle to economic growth in developing countries (DVCs) is often found in the financial markets, particularly the availability of savings which is critical for investment. When considering the choices provided, the low supply of saving fundamentally stands out as a major obstacle to economic growth.
On to the related question about financial markets: The change that will lead to a decline in interest rates is a rise in supply of finance, such as savings or loanable funds. This is because when the supply of money available for lending increases, lenders have more capital to offer borrowers, so they will reduce the interest rates to attract more borrowers. Conversely, when supply falls or demand rises, interest rates are likely to increase in order for lenders to capitalize on the higher competition for the same amount of loanable funds. This is akin to the law of supply and demand, where an increased supply of a good or service, assuming demand remains constant, typically results in a lower price.