Adecline in the number of pancreatic beta cells is characteristic of the disease called:

A decline in the number of pancreatic beta cells i a characteristic of diabetes mellitus.

Explanation:

All right, Diabetes mellitus is a condition in which the pancreas stops producing endogenous insulin-like it used to be. So insulin levels are lower, this is produced by the destruction of pancreatic beta cells. Also, this is the major difference between diabetes type 1 and type 2. It is not a sickness, just a condition and even though it can be very exhausting is not that alarming. Someone can start a good life with diabetes mellitus.

i believe the answer would be 'd'.

hope this !