Answer: B
E11.9 is the appropriate code for this cause because it specifies Diabetes Mellitus II without complications. The type of diabetes is unknown so the default is type 2 DM.
Option A is not correct because E11.8 code is used for type II DM when complications are not specified. As the patient is doing well, no complications are assumed.
Option C is not correct because E11.10 is used to code for Type 2 DM with ketoacidosis without a coma. Ketoacidosis is not mentioned in this patient.
Option D is not correct because D11.36 is used to code for type I DM with diabetic cataract which is not given in the question.