**Core Concept**
At around 2 years of age, children typically develop the ability to form short sentences with 2-3 words, marking a significant milestone in language development. This stage is often referred to as "two-word phrases" or "telegraphic speech." The underlying principle being tested is the developmental timeline of language acquisition in infants and toddlers.

**Why the Correct Answer is Right**
The correct answer reflects the average age at which children typically develop the ability to form short sentences. This is a result of significant cognitive and linguistic advancements, including improved vocabulary, grammar, and syntax. Around 2 years of age, children's brains are wired to recognize and mimic complex sentence structures, enabling them to communicate more effectively. This is also a period of rapid language expansion, where children learn new words and phrases at an incredible rate.

**Why Each Wrong Option is Incorrect**
**Option A:** 6 months - At this age, babies are just beginning to babble and make cooing sounds, but they are not yet forming short sentences.
**Option B:** 1 year - While 1-year-olds are making significant progress in language development, they are still primarily using single words and short phrases.
**Option C:** 3 years - Children typically develop more complex sentence structures and vocabulary at this age, but the ability to form short sentences with 2-3 words is generally established by 2 years.

**Clinical Pearl / High-Yield Fact**
Remember that language development is a gradual process, and every child progresses at their own pace. However, if a child is not making significant progress in language development by 18 months, it is essential to consult with a pediatrician or a speech-language pathologist to rule out any underlying developmental delays or disorders.

**Correct Answer:** C. 2 years