The correct answer is D) interest helps them cover business costs.
What best explains why banks consider interest on loans to be important is that interest helps them cover business costs.
Banking is big business. When banks loans money they automatically charge you interest. It is called the interest rate. This represents a profit, among the many ways they have to make a profit. This money also helps banks to cover expenses and business costs.
The other options of the question were A) interest helps them to control the economy, B) interest helps them to satisfy customers, and C) interest enables them stockpile money.
