Upon a deep analysis of the elemental, hierarchical structure, and psychological bases of Charles Spearman's 'Two-Factor Theory of Intelligence' and Howard Gardner's 'Theory of Multiple Intelligences', which of the following statements regarding the fundamental differences and assumptions between these two theories is most authentic and scientifically true?

Charles Spearman propounded the Two-Factor Theory of Intelligence in 1904, according to which intellectual ability includes a general factor (g-factor) and several specific factors (s-factors). In contrast, Howard Gardner propounded the Theory of Multiple Intelligences in 1983, in which he divided intelligence into several independent types of abilities (such as linguistic, logical-mathematical, musical, etc.) rather than a single general capacity. This approach moves away from psychological testing and factor analysis to reflect cognitive diversity.