Answer:
Telegraphic Speech.
Step-by-step explanation:
The Telegraphic Stage of the Language Development occurs at the age of two or two-and-a-half years. The term 'telegraphic' is used in relation to the words that we use in telegraphs, short. The term was fabricated by Roger Brown and Colin Fraser in 1963 in their book titled 'The Acquisition of Syntax.'
The child instead of saying the whole grammatically correct sentences begin to form short sentences such as given in the question.
The words that are being uttered by Sammy are telegraphic. Thus the stage of language development at which Sammy is the Telegraphic Speech.
So, the correct answer is Telegraphic Speech.