Which of the Following Statements Best Describes the Theory of Conservation

Which of the following statements best describes the theory of Conservation of Orbital Symmetry?

A) Molecular orbital of the transition state must be similar to that of the reactant.
B) Molecular orbital of the transition state must be similar to that of the product.
C) Only s orbitals from reactants and products are utilized.
D) Molecular orbitals of reactant and product must have similar symmetry.
E) Molecular orbitals of reactant and product must have different symmetry.