Answer: The right answer is the A) Nick trusts Arif.
Explanation: There are no references to dogs in the passage, and Arif seems to have changed his mind and have accepted Nick's invitation to the concert, so options D and C are incorrect. In addition, it cannot be inferred that Nick thinks that Arif is irresponsible, since he is inviting him to go with him and another friend to a concert, so option B should be eliminated as well. Therefore, and since Nick seems to be genuinely inviting Arif to a concert, and presumably meeting with him at his house, it can be inferred that he trusts Arif.