The Adjective Clause in the given sentence is: who has industrious habits.

Here's why:

• An Adjective Clause provides additional information about a noun or pronoun and functions like an adjective.
• In this sentence, "who has industrious habits" modifies the noun "man" by describing the man's characteristics. It acts like an adjective phrase answering the question "what kind of man?"
• The other options are not Adjective Clauses:
  • "industrious habits" is the object of the verb "has" and not modifying any noun.
  • "sure to succeed" is an adverbial phrase modifying the verb "is" and not describing the noun "man."
  • "A man" is the subject of the sentence, not an Adjective Clause.

Therefore, considering its function of modifying the noun and providing additional information, "who has industrious habits" effectively identifies the Adjective Clause in the given sentence.