28. Which following group of m/z signals belongs to the fragments of the shown compound in its mass spectrum? (A) 29, 71, 76, 104, 107 (D) 29, 71, 73, 87, 101 (B) 45, 74, 76, 90 (E) 45, 74, 93, 104, 107 (C) 29, 74, 76, 101, 104