Topic: Affirmative Negative Agreement,

Best Answer Explained in Below-:

The sentence "He is hard working and ___ ." requires a completion that accurately reflects agreement with the statement about the subject "He." When analyzing the options given:

A) "I am so" – This structure doesn’t properly maintain the parallelism needed in the sentence.

B) "so I am" – This response suggests that the speaker is hard working as well, but it doesn’t fit the flow of the original sentence.

C) "so am I" – This is the correct choice. It uses the inversion that is typical for agreeing with a statement about someone else. The phrase "so am I" emphasizes that the speaker shares a similar quality (being hardworking) with "He."

D) "I too am" – Although this option is also grammatically correct, it is less common and sounds somewhat more formal.

In conversational English, "so am I" effectively communicates agreement in a concise and natural way. This is why option C is the most appropriate choice to complete the sentence.