Which of the following stages of Piaget's cognitive development takes place from ages 7 to 11?

The correct answer is A. Concrete operations. During ages 7 to 11, children are in the stage of concrete operations according to Piaget's theory of cognitive development. In this stage, children are able to think logically about concrete events and understand conservation and mathematical transformations.

Options B, C, and D are incorrect: B. Formal operations: This stage occurs around ages 12 and onward, where individuals can think logically about abstract concepts and hypothetical situations. C. Preoperational: This stage occurs around ages 2 to 7, where children are egocentric and struggle with understanding the perspectives of others. D. Sensorimotor: This stage occurs from birth to age 2, where infants learn through their senses and actions, gradually developing object permanence.