The correct answer is B. Optimistic
Step-by-step explanation:
In texts, the tone refers to the attitude or position of the author towards the subject of the text that can be positive, negative, optimistic, sarcastic, etc. and is determined by the use of the language of the author. In the case of the passage presented this mainly explains the attitude of Natasha and for doing this the author uses expression such as "she was always smiling", "she would do better next time" and "Her friends were impressed by how positive she was" that shows the author of this text mainly has a positive attitude towards Nashaha and her behavior and therefore the tone, in this case, is Optimistic.