Which of the following factors concern the size of the investment?

The factor that concerns the size of the investment is leverage. Leverage refers to the use of borrowed funds to increase the potential return on an investment. The concept is inherently tied to the size of the investment because by employing leverage, an investor can control a larger asset base than they could with their own capital alone. This amplifies both the potential gains and potential losses on the investment, making it a critical consideration for investors when assessing the scale and risk of their financial commitments.

Management, holding period, and safety of investment, while important aspects of investment strategy, do not directly address the size of the investment in the same way. Management focuses on how well an investment is handled, the holding period pertains to the duration for which an asset is retained, and safety of investment relates to the risk associated with potential losses. None of these factors pertain specifically to the size of the investment in the manner that leverage does.