Answer:
D.
Step-by-step explanation:
A is wrong because Oregon should be capitalized as it is a proper noun. Also, 'itselves' is wrong because 'it' is a singular pronoun; it should be 'itself.'
B is wrong because 'themselves' is used for a singular noun (eruption); it should be 'itself.'
C is wrong because Oregon should be capitalized as it is a proper noun.