A long rectangular bar 20 mm wide and 10 mm thick made of hot-rolled 4340 carbon steel (Sy = 860 MPa, K1c = 99 MPaÖm), is found to have a centrically located through-thickness crack 8mm wide. Is it best to a) leave the crack alone, b) drill a 5 mm diameter hole through the center of the crack, or c) completely drill out the crack with a 10 mm hole?