**Core Concept**
The question is testing the child's developmental milestone of hugging, which is a sign of affection and attachment. This milestone is typically achieved around a certain age, marking a significant emotional and social development in children.

**Why the Correct Answer is Right**
The correct answer is based on the child's cognitive and emotional development. Around 12-24 months of age, children start to develop a sense of attachment and affection towards their caregivers, which is manifested through physical gestures like hugging. This milestone is an essential part of social and emotional development, and it is a significant indicator of a child's ability to form healthy relationships.

**Why Each Wrong Option is Incorrect**
**Option A:** This option might be tempting, but hugging is typically not seen in children before 9-12 months of age, as they are still learning to navigate their surroundings and developing trust in their caregivers.

**Option B:** This option is incorrect because children usually start to show affection through hugging around 12-24 months of age, not immediately after sitting up.

**Option C:** This option is incorrect because children typically start to show affection through hugging around 12-24 months of age, not immediately after saying their first words.

**Clinical Pearl / High-Yield Fact**
A child's ability to hug their parents is a significant indicator of their emotional and social development. It marks a significant milestone in their ability to form healthy relationships and demonstrates their growing sense of attachment and affection towards their caregivers.

**Correct Answer:**.