Let \( \mathbb{R}^2 \) denote \( \mathbb{R} \times \mathbb{R} \). Let \( S = \{ (a, b, c) : a, b, c \in \mathbb{R} \} \) and \( ax^2 + 2bxy + cy^2 > 0 \) for all \( (x, y) \in \mathbb{R}^2 - \{(0, 0)\} \). Then which of the following statements is (are) TRUE?