**Question:** A child climbs stairs at: March 2013 (b, c, e, h)

**Core Concept:** Motor Development in Children

Motor development refers to the gradual improvement in motor skills that allows children to perform complex tasks, such as climbing stairs. This process involves the integration of neurological, musculoskeletal, and sensory systems. In the context of the provided options, we need to identify the specific milestone achieved by a child in March 2013.

**Why the Correct Answer is Right:**

The correct answer, **Option D**, represents the milestone of climbing stairs independently, with no assistance from others. This milestone typically occurs around the age of 18-24 months (1 ½ to 2 years old). By this age, the child has developed the strength, coordination, and cognitive understanding required to ascend and descend stairs safely.

**Why Each Wrong Option is Incorrect:**

Option A (March 2012) is too early for a child to climb stairs independently. Motor milestones generally progress sequentially and are not typically achieved before the appropriate age.

Option B (March 2014) is too late for a child to achieve this milestone. A child typically masters climbing stairs between 18-24 months, not at 24 months.

Option C (March 2013) is the correct answer, but let's further elaborate on the milestone.

Option E (March 2015) is too late for a child to climb stairs independently. This milestone is usually achieved by 18-24 months.

Option H (March 2017) is too late for a child to climb stairs independently. Motor milestones progress gradually, and this milestone is typically achieved by 18-24 months.

**Clinical Pearl / High-Yield Fact:**

The milestones of motor development are crucial to monitor in children, as they provide insights into the child's overall neurological, musculoskeletal, and cognitive development. Delayed motor milestones may indicate a need for further evaluation by a pediatrician or developmental specialist.

**Correct Answer:**

**D.** March 2013

By March 2013, a child should be able to climb stairs independently due to the development of motor skills, coordination, and understanding of gravity, space, and the concept of "up" and "down." This milestone represents the child's ability to balance, control their body, and understand the spatial relationship between different levels.

The correct answer is March 2013, as it is within the typical age range of 18-24 months when children can achieve this milestone. Delayed motor milestones can indicate a need for further evaluation by a pediatrician or developmental specialist.