Which two methods are valid for calculating field values? (Choose two)

The method involving VB calculations requiring field names to be enclosed in square brackets is valid. This is a specific syntax rule in Visual Basic for Applications (VBA), where square brackets are used to denote field names within the calculation expressions. Using square brackets helps differentiate field names from other elements, such as functions or variables, ensuring that the expression is correctly interpreted by the software.

The method stating that only selected records will be calculated if any records in the table are selected is also appropriate. In ArcGIS, when performing calculations on fields, the operations will apply only to records that have been selected. This selective approach allows for more precise data manipulation without affecting the entire dataset, making it a practical method for users who wish to focus calculations on a subset of the data.