The risk of tank failure due to brittle fracture is considered minimal after what condition(s)?

The tank has demonstrated its ability to withstand the combined effects of maximum liquid level (highest stresses) and highest operating temperature

The tank has demonstrated its ability to withstand the combined effects of intermediate liquid level (highest stresses) and lowest operating temperature

The tank has demonstrated its ability to withstand the combined effects of maximum liquid level (highest stresses) and lowest operating temperature

The tank has demonstrated its ability to withstand the combined effects of maximum liquid level (highest stresses) and intermediate operating temperature