If universe of disclosure are all real numbers, then which of the following are true?
(A) ∃x ∀y (x + y = y)
(B) ∀x ∀y (((x ≥ 0) ∧ (y < 0) → (x - y > 0))
(C) ∃x ∃y (((x ≤ 0) ∧ (y ≤ 0) ∧ (x - y > 0))
(D) ∀x ∀y ((x ≠ 0) ∧ (y ≠ 0) ↔ (xy ≠ 0))
Choose the correct answer from the options given below:
1
(A) and (B) Only
2
(C) and (D) Only
3
(A), (B) and (D) Only
4
(A), (B), (C) and (D) Only