Answer:
The Formal Stage
Explanation:
The Stages of cognitive development are as follows:
The Sensorimotor Stage, which is what babies go through, and consists of touchy-feely actions. The name comes from "Sensor" (feelings, nerves) and "Motor" or actions and movements.
The Preoperational Stage is when younger children begin to develop reading and writing skills, along with speech and recognization skills.
The Concrete Operational Stage is where kids start thinking more logically, instead of pretend situations. For example, a boy might understand a dog will play with him if he is calm and collected, instead of when he is rough and loud, thus scaring the dog away.
The Formal Operational Stage is when older kids start to make more logical conclusions through running tests and collecting data in a organbized way. This is when the child begins thinking like an adult.
Based on the information given, Bob best fits the 4th stage, Formal, because he chooses to do systematic tests to find what the liquid is.
