The Crowding Out Effect is a prominent macroeconomic concept associated with expansionary fiscal policy and deficit financing.

Option A is incorrect: A situation where private investment increases due to increased government spending is known as the Crowding In Effect. This typically happens during a deep recession when government spending boosts aggregate demand, improving business expectations and encouraging private investment despite potential interest rate changes.

Option B is correct: The Crowding Out Effect occurs when the government runs a budget deficit and borrows heavily from the financial market to finance its increased spending. This massive borrowing increases the overall demand for a limited pool of loanable funds. The heightened competition for capital drives up the equilibrium interest rates. Higher interest rates make borrowing more expensive for private businesses and consumers, leading to a decline in private sector investment. Thus, the private sector is effectively "crowded out" of the credit market.

Option C is incorrect: An increase in taxes generally reduces the disposable income of consumers and the retained earnings of businesses, which typically leads to a decrease, not an increase, in private sector investment and consumption.

Option D is incorrect: Government spending directly adds to aggregate demand. The crowding out effect argues that the net impact on aggregate demand might be smaller than expected because the increase in government spending is partially offset by a decrease in private investment, but it does not mean government spending has zero impact.

Therefore, Option B is the correct answer.