A magnesium strip is burnt in air to form magnesium oxide. Which statement is correct?

A、Twoelementsarejoinedtogethertoformamixture.
B、Anelementandcompoundarejoinedtogethertoformanothernewcompound
C、Twoelementsarejoinedtogethertoformacompound.
D、Twocompoundsarejoinedtogethertoformanelement.