Final answer:
The correct statement is that measurement is concerned with how economic effects should be quantified. Measurement is central in determining the value of economic effects for financial reporting and contributes to macroeconomic indicators such as GDP.
Step-by-step explanation:
The statement that is true among the given options is: a. Measurement is concerned with how economic effects should be quantified. This involves determining the value or quantity of the economic effects of transactions and other events in a way that they can be recorded in the financial statements. Measurement is an essential aspect of accounting and finance, providing valuable information that informs various economic analyses, including the gross domestic product (GDP), which is a measurement of the size of the economy. Including both the quantity and the prices of goods and services produced, GDP provides a quantitative indicator of economic performance and stability.
Regarding the other options, b refers to the entity concept, which is about defining the boundaries of the reporting entity. c refers to recognition, which involves deciding which economic effects should be recorded in the financial statements, not just the dollar amount. d refers to the assumption that economic activities are measured in monetary units, but not necessarily in terms of current purchasing power.