The words ended and theory
D is correct.
Hope this helps and please give brainliest!
In the sentence pattern for asking questions, the subject is placed immediately after the operator (Operator [did, does, was] + Subject) while in the sentence pattern for making statements, the subject is placed before the verb phrase (Subject + VP). However, some statements may be in question form (You've already eaten?) and some questions (such as rhetorical ones) may be in statement form (Haven't you peed already?).
