Construct a derivation to show the following. Do not use any rules for disjunction other than PC and PE; in particular, do not use the rules MTP and Wk that are introduced in §4.3:

(A ∧ B) ∨ C ⊨ B ∨ (C ∨ D)

(Hint: If you exploit the resource at the first stage, you will have an opportunity to plan for the goal differently in the two case arguments.)