Given that ∠XQR = 180° and ∠LQM = 180°, which equation could be used to solve problems involving the relationships between ∠XQM and ∠RQM? A) 180 + (140 − 7a) = (70 − 3a) B) 180 + (70 − 3a) = (140 − 7a) C) 180 − (140 − 7a) = (70 − 3a) D) (140 − 7a) − (70 − 3a) = 180