Which of the following is/are correct about C. Vijayaraghavachariar?
I. He was called ‘The Hero of Salem’.
II. He was known as the ‘Lion of North India’.

The correct option is Only I.

Let us analyze the given statements step-by-step:

Statement I: He was called ‘The Hero of Salem’.
This statement is correct. Chakravarti Vijayaraghavachariar (1852–1944) was an eminent Indian freedom fighter, lawyer, and politician. In 1882, communal violence broke out in Salem (located in present-day Tamil Nadu). Vijayaraghavachariar was falsely implicated, arrested, and sentenced to imprisonment. He fought his case in the courts, successfully proved his innocence, and secured his release. His brave legal battle and leadership during this crisis earned him the title of "The Hero of Salem".

Statement II: He was known as the ‘Lion of North India’.
This statement is incorrect. Vijayaraghavachariar spent his life and political career primarily in South India (Madras Presidency). The title 'Lion of North India' is not associated with him. Historically, titles like "Lion of Punjab" (Sher-e-Punjab) were used for other prominent nationalist leaders, such as Lala Lajpat Rai.

Since only the first statement is correct, the correct option is Only I.