Directions (1-6): In the following questions, a sentence is divided into four parts. Choose the part of the sentence which may contain a grammatical error in it. If all the parts of the sentence are grammatically correct and contextually meaningful, choose option “no error” as your answer choice.

After finishing the (A)/ marathon, she treated himself (B)/ to a delicious meal (C)/ to celebrate her accomplishment. (D)

The correct option containing a grammatical error is B.

Step-by-step Explanation:
1. Analyze the Subject: The subject of the sentence is "she" (a third-person singular female pronoun), introduced in the clause starting in part (B).
2. Identify the Pronoun Agreement: In part (B), the sentence states "she treated himself". The reflexive pronoun used here is "himself", which is masculine and does not agree with the feminine subject "she".
3. Correction: To correct the error, the reflexive pronoun must match the gender and number of the subject. Therefore, "himself" must be replaced with "herself".
4. Review the corrected sentence: "After finishing the marathon, she treated herself to a delicious meal to celebrate her accomplishment." This makes the sentence grammatically correct and contextually meaningful.