To identify the possessive noun in the sentence "My office car is parked elsewhere," we need to understand what a possessive noun is. A possessive noun shows ownership, typically formed by adding an apostrophe and 's' at the end of a word. The options provided are:
- Car's
- Office's
- Mother's
- Friend's
In the sentence, "office car" indicates a description rather than possession, meaning neither "Car's" nor "Office's" fits. "Mother's" and "Friend's" are possessive nouns, but they do not appear in the sentence. Therefore, despite being marked as the correct answer, "Mother's" is unrelated. As the sentence provides no possessive noun, none of the options are valid for the given sentence.