<prompt> Most common cause of primary hyperparathyroidism ?HyperplasiaSolitary AdenomaCarcinomaMultiple adenomas  <response>: Ans. is b i.e., AdenomaHyperparathyroidismHyperparathyroidism is caused by elevated parathyroid hormone.Primary hyperparathyroidism : an autonomous overproduction of parathyroid hormone PTH, usually resulting from an adenoma or hyperplasia of parathyroid tissue. 