Final answer:
The most grammatically correct sentence is 'Maria mentioned she would bring ice cream to the dinner party.'
Step-by-step explanation:
The most grammatically correct sentence from the given options is: Maria mentioned she would bring ice cream to the dinner party.
In this sentence, the verb 'bring' is used in the correct form 'would bring' to indicate a future action. 'Brought' is the past tense of 'bring' and does not fit in the sentence. Furthermore, 'brung' is not a standard English word. 'Will brung' is also incorrect as it combines the present tense 'will' with the incorrect form 'brung'.
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