Which best statement describes an element?

Which best statement describes an element?
  a. A substance that cannot burn.
  b. A substance that is soluble in both acid and base
  c. A substance that is held together by covalent bonds
  d. A substance that is composed of more than one kind of atom
  e. A substance that cannot be broken into simpler substances by chemical reactions

Question 2

What differentiates an organic compound from an inorganic compound?
  a. An organic compound lacks isotopes.
  b. An organic compound contains carbon.
  c. An organic compound lacks valence electrons.
  d. An organic compound is basic rather than acidic.
  e. An organic compound contains two or more atoms