Which of the following statements are true?
A. Truth and falsehood are attributes of individual propositions.
B. Validity can never apply to any single proposition by itself.
C. In a valid argument, all of its premises have to be true.
D. A valid deductive argument cannot have all true premises and a false conclusion.
Choose the most appropriate answer from the options given below:

The correct option is A, B and D only.

Let us analyze each statement step-by-step to understand why this option is correct:

Statement A: Truth and falsehood are attributes of individual propositions.
This statement is true. In logic, a proposition is a declarative statement that asserts something to be the case. Every proposition is either true or false. Therefore, truth and falsehood are properties belonging to individual propositions.

Statement B: Validity can never apply to any single proposition by itself.
This statement is true. Validity is a structural property of arguments, which consist of a relationship between multiple propositions (premises and a conclusion). A single proposition on its own cannot be valid or invalid; it can only be true or false.

Statement C: In a valid argument, all of its premises have to be true.
This statement is false. An argument is valid if its structure guarantees that if the premises were true, the conclusion must be true. A valid argument can actually contain false premises. For example, "All birds have eight legs (False). All eight-legged creatures can speak French (False). Therefore, all birds can speak French (False)" is a structurally valid argument even though the premises and conclusion are all false.

Statement D: A valid deductive argument cannot have all true premises and a false conclusion.
This statement is true. By definition, a deductive argument is valid if and only if it is impossible for all of its premises to be true and its conclusion to be false at the same time. If the premises are all true, the truth of the conclusion is logically guaranteed.

Therefore, statements A, B, and D are true, while statement C is false.