**Question:** A child changes rattle from one hand to the other hand at the age of:

**Core Concept:**
The development of hand-eye coordination in children is a crucial aspect of their cognitive and motor skill development, which is achieved through various stages. The ability to switch attention between objects is a critical milestone in this process.

**Why the Correct Answer is Right:**
The correct answer, **C. 18 months**, refers to the age when a child typically exhibits the ability to shift their attention from one object to another, in this case, from one hand to the other when holding a rattle. This developmental milestone demonstrates the child's improved cognitive function and fine motor skills.

**Why Each Wrong Option is Incorrect:**
A. **6 months**: This is too early, as hand-eye coordination and attention-switching skills develop over time, and this age doesn't provide sufficient development of cognitive and motor skills.
B. **3 years**: This is too late, as the ability to switch attention between objects usually occurs between 12-18 months.
D. **12 months**: Though the child may grasp objects with both hands, this does not necessarily indicate the ability to switch attention between objects, as it is a simpler fine motor skill.

**Why the Correct Answer is Right:**
Hand-eye coordination and attention-switching are crucial aspects of child development, which contribute to their cognitive and motor skill growth. The ability to change between objects, such as from one hand to the other, demonstrates an improvement in these skills.

**Why Each Wrong Option is Incorrect:**
A. **6 months**: This is too early, as hand-eye coordination and attention-switching skills develop over time, and this age doesn't provide sufficient development of cognitive and motor skills.
B. **3 years**: This is too late, as the ability to switch attention between objects usually occurs between 12-18 months.
D. **12 months**: Though the child may grasp objects with both hands, this does not necessarily indicate the ability to switch attention between objects, as it is a simpler fine motor skill.

**Core Concept:**
Hand-eye coordination and attention-switching are essential aspects of child development that contribute to their cognitive and motor skill growth. The ability to change between objects, such as from one hand to the other when holding a rattle, demonstrates an improvement in these skills.

**Why Each Wrong Option is Incorrect:**
A. **6 months**: This is too early, as hand-eye coordination and attention-switching skills develop over time, and this age doesn't provide sufficient development of cognitive and motor skills.
B. **3 years**: This is too late, as the ability to switch attention between objects usually occurs between 12-18 months.
D. **12 months**: Though the child may grasp objects with both hands, this does not necessarily indicate the ability to switch attention between objects, as it is a simpler fine motor skill.

**Clinical Pearls:**
Switching between objects, such as from one hand to the other while holding a rattle, is an important milestone in a child