**Core Concept**
Frey's procedure is a surgical intervention aimed at treating chronic pancreatitis, specifically involving the drainage of pancreatic pseudocysts and the decompression of the pancreas. This procedure is a modification of the original procedure described by Frey and Brooks.

**Why the Correct Answer is Right**
Frey's procedure involves two main components: the longitudinal pancreaticojejunostomy (LPJ) and the resection of the diseased pancreatic tissue. The LPJ involves the creation of a side-to-side anastomosis between the pancreatic duct and the jejunum, allowing for the drainage of pancreatic secretions and the relief of obstruction. The resection of the diseased pancreatic tissue involves the removal of the affected portion of the pancreas, which helps to reduce pain and inflammation.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because Frey's procedure is not primarily used for the treatment of pancreatic cancer. While it may be used to palliate symptoms in advanced cases, it is not a curative treatment for cancer.
**Option B:** This option is incorrect because the Puestow procedure is a different type of surgical intervention for chronic pancreatitis, which involves the creation of a pancreaticojejunostomy without resection of pancreatic tissue.
**Option C:** This option is incorrect because the treatment of choice for pancreatic pseudocysts often involves drainage or resection of the pseudocyst, but Frey's procedure is a more comprehensive approach that involves both drainage and resection.

**Clinical Pearl / High-Yield Fact**
Frey's procedure is often indicated in patients with chronic pancreatitis who have failed medical management and have significant pain and pancreatic ductal dilation.

**Correct Answer: D. Treatment of chronic pancreatitis.**