Final answer:
The term 'Variant Cast Exception' correctly describes the error occurring when the system fails to cast a variant value to a fixed type due to a type mismatch in programming.
Step-by-step explanation:
The error message 'failed to cast variant value to fixed' indicates that there has been an issue in attempting to convert a value from a variant or dynamic type to a fixed type in a programming or computing context. The correct term for this error would be Variant Cast Exception (A). This kind of error occurs when the actual type of the value does not match the expected fixed type, and thus, the system is unable to perform the cast operation. Errors like this are often encountered in strongly typed programming languages when an explicit conversion or cast is performed between incompatible types.