If injections increase, then national income will tend to increase, but it does not necessarily mean that leakages will tend to decrease. It is possible that both injections and leakages increase or decrease at the same time.
Choices A and B are true statements about the circular flow of income model: it shows interdependence because the flows of inputs, outputs, income, and expenditure contribute to each other. For example, income paid to households becomes expenditure on production.
Choice C is also true: if the sum of export revenue, government expenditure, and investment expenditure is smaller than that of import expenditure, taxes, and saving, then the value of national income will decrease.
