Explanation:

- A man's signature of his own name can amount to forgery if used with intent to defraud. Forgery involves making a false document or altering a genuine one with intent to deceive.

- Option 1: True - A man's own signature can be forgery if done with criminal intent.

- Option 2: Cannot say - In some cases, we might lack sufficient information to determine intent, but forgery is possible.

- Option 3: False - Incorrect, as personal signatures can still be used to commit forgery.

- Option 4: None of the above - Incorrect, one option indeed applies.