Final answer:
The sentence using 'it' correctly is A: 'The baby giraffe loves to peek its head over the top of the fence,' where 'its' is the possessive form indicating ownership.
Step-by-step explanation:
When it comes to using the correct form of "it", the sentence that uses it properly is A. The baby giraffe loves to peek its head over the top of the fence. The word its in this sentence is a possessive pronoun, which does not require an apostrophe. It is indicating that the head belongs to the baby giraffe. In contrast, it's is a contraction for "it is" or "it has", which is incorrectly used in the other sentences provided.
In English, it's essential to differentiate between it's and its to ensure that sentences are grammatically correct. The possessive form its signifies ownership, while the contraction it's represents "it is" or "it has". For example, one could say, "It's [it is] going to rain today," or "The cat chased its tail." Remembering this distinction is vital for avoiding common grammatical errors in writing.