In the figure below, line s is parallel to DE.

Which statements must be true?
Select all that apply.

A. ∠a ≅ ∠c
B. m∠b + m∠d + m∠e = 180°
C. (m∠a + m∠b) - m∠d = m∠b
D. (m∠a + m∠b + m∠c) - (m∠d + m∠a) = m∠b
E.(m∠a + m∠b + m∠c) = (m∠b + m∠d + m∠e)
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