Capital Formation: This refers to the addition to the existing stock of physical and human capital in an economy.

High Savings: High savings provide the necessary funds for investment. However, savings alone do not guarantee growth; the efficiency with which those savings are converted into output is crucial.

Capital-Output Ratio (COR): This ratio indicates the amount of capital required to produce one unit of output.

• A low ratio means capital is efficient.
• A high ratio means capital is inefficient (more capital is needed for the same amount of output).

Why (D) is correct: Even if an economy saves and invests heavily (capital formation), if the Capital-Output Ratio is high, the resulting increase in output (GDP) will be low. This often happens due to technological backwardness, poor infrastructure, or inefficient management of resources.