ANS:A - impact strength

The notched bar test, commonly known as the Charpy or Izod impact test, is used for testing the impact strength of a material. Impact strength refers to the ability of a material to withstand sudden, dynamic loading without fracturing. The notched bar test involves striking a notched specimen with a pendulum, and then measuring the energy absorbed by the specimen as it fractures. This energy absorption indicates the material's resistance to impact loading. So, the correct answer is: impact strength.