**Core Concept**
Apexification procedures are used to induce calcification of the root tip in immature teeth with non-vital pulp. Calcium hydroxide is a key component in this process, as it promotes the formation of a calcific barrier and helps to seal the canal. However, excess calcium hydroxide can lead to periapical issues.

**Why the Correct Answer is Right**
The correct answer is **C. Will be removed by multinucleated giant cells**. This is because multinucleated giant cells, a type of immune cell, play a crucial role in the body's response to foreign materials, including calcium hydroxide. These cells recognize and engulf the excess calcium hydroxide, breaking it down and removing it from the periapical tissues. This process is an essential part of the body's defense mechanism against harmful substances.

**Why Each Wrong Option is Incorrect**

* **Option A:** Excess calcium hydroxide can cause necrosis in the periapical tissues, but multinucleated giant cells do not directly cause necrosis. Instead, they help to remove the excess calcium hydroxide, which can prevent necrosis.
* **Option B:** Excess calcium hydroxide does not resorb on its own; instead, it needs to be removed by the body's defense mechanisms, such as multinucleated giant cells.
* **Option D:** Apicoectomy is a surgical procedure that may be required if the excess calcium hydroxide causes significant periapical issues, but it is not the primary mechanism for removing excess calcium hydroxide.

**Clinical Pearl / High-Yield Fact**
It's essential to monitor the periapical tissues during apexification procedures and remove excess calcium hydroxide to prevent periapical issues. Multinucleated giant cells play a crucial role in this process, and their presence can indicate a successful removal of excess calcium hydroxide.

**✓ Correct Answer: C. Will be removed by multinucleated giant cells**