Muscle phosphorylase deficiency leads to which glycogen storage disorder: (A) Hers disease, (B) McArdles disease, (C) Cori's disease, (D) Andersen disease
Answer is B. Muscle phosphorylase deficiency leads to McArdle's disease. (Mnemonic "M for M') which is characterised by poor exercise tolerance, Muscle glycogen being abnormally high and blood lactate level very low after exercise.
Mnemonic

Heri's disease - Hepatic phosphorylase
Andersen disease - Branching enzyme
Cori's disease - Debranching enzyme.