Which of the following psychological statements is most authentic and scientifically valid regarding the true psychological implications of 'Conservation'—a central concept under Jean Piaget's Theory of Cognitive Development defined as the mental ability to understand that mass, volume, weight, or quantity remains constant despite changes in physical form, shape, or appearance—and its application to logical thinking and mathematical-scientific concepts in classroom teaching?

According to Jean Piaget's Theory of Cognitive Development, the emergence and development of the ability of 'Conservation' primarily takes place during the Concrete Operational Stage (approximately 7 to 11 years). During this stage, the child becomes capable of understanding that changing the color, form, shape, or container of an object does not affect its total quantity (mass, volume, or weight). Two main mental processes work behind this: Decentration (focusing on multiple aspects of an object at the same time) and Reversibility (the ability to mentally reverse a process). Therefore, option (B) is the most authentic and scientifically valid statement.