Which of the following is true according to Piaget's concept of conservation?
◦ The ability rarely occurs before age 9.
◦ The ability requires being able to adopt the perspective of others.
◦ It means that a child will not be fooled by an apparent change in volume if water is poured from a short, wide glass into a taller, thinner glass.
◦ It requires the ability to mentally manipulate symbolic external characteristics in the absence of visual cues.