Fredrick purchased a property worth $150,000 on mortgage. He had paid $30,000 as a down payment on this property. However, because of a recent slump in the real estate prices, the property is worth only $110,000, forcing Fredrick to sell the property. Assuming that no mortgage payments have been made by Fredrick, this sale is termed a(an) _____.
fixed mortgage sale
real estate short sale
real estate declining equity
shrinking principal sale
indexed equity