**Core Concept**
The parathyroid glands play a crucial role in calcium homeostasis by secreting parathyroid hormone (PTH). PTH maintains serum calcium levels by promoting calcium release from bones, increasing calcium absorption from the gut, and reducing calcium excretion by the kidneys.

**Why the Correct Answer is Right**
Removal of a parathyroid gland leads to a decrease in PTH secretion, resulting in decreased bone resorption, decreased calcium absorption from the gut, and increased calcium excretion by the kidneys. This ultimately causes a decrease in serum calcium levels, leading to hypocalcemia.

**Why Each Wrong Option is Incorrect**
* **Option A:** Decreased PTH secretion would decrease bone resorption, but this option is not directly related to the removal of a parathyroid gland.
* **Option B:** This option is correct, as removal of a parathyroid gland would lead to decreased PTH secretion, which would decrease calcium absorption from the gut.
* **Option C:** This option is correct, as removal of a parathyroid gland would lead to decreased PTH secretion, which would increase calcium excretion by the kidneys.

**Clinical Pearl / High-Yield Fact**
In the case of parathyroid gland removal, it is essential to monitor serum calcium levels closely, as hypocalcemia can lead to severe clinical manifestations, including tetany, seizures, and cardiac arrhythmias.

**Correct Answer: B. This option is correct, as removal of a parathyroid gland would lead to decreased PTH secretion, which would decrease calcium absorption from the gut.**