What is the Delphi technique used for in the validation process of nursing diagnoses?

The Delphi technique is used to validate the content of nursing diagnoses.
The Delphi technique is used to validate the clinical validity of nursing diagnoses.
The Delphi technique is used to validate the demographic validity of nursing diagnoses.
The Delphi technique is used to validate the discriminant validity of nursing diagnoses.
a) Only statement 1 is correct.
b) Statements 1 and 2 are correct.
c) Statements 1 and 3 are correct.
d) Statements 1 and 4 are correct.