Macewen's sign, characterized by a 'cracked pot' sound upon percussion of the skull, is typically associated with which condition?

Given below are two statements: one is labelled as Assertion (A) and the other as Reason (R). Assertion (A): Patients diagnosed with Type 1 Diabetes Mellitus require lifelong insulin therapy. Reason (R): Type 1 Diabetes Mellitus is characterized by an autoimmune destruction of pancreatic β-cells, leading to an absolute deficiency of insulin. In light of the above statements, choose the most appropriate answer:

'Bulimia Nervosa' can lead to a specific electrolyte imbalance known as 'Hypokalemia', which is a deficiency of: