## Core Concept
The question pertains to the natural elements known for their anticancer properties. This involves understanding the role of various elements in cancer prevention and treatment.

## Why the Correct Answer is Right
Selenium (Se) is a trace element that has been recognized for its anticancer properties. It acts through various mechanisms, including the formation of selenoproteins, which have antioxidant and anti-cancer effects. Selenoproteins can help protect cells from damage and may play a role in preventing the growth of cancer cells. Selenium is a component of glutathione peroxidase, an enzyme that helps reduce oxidative stress in cells, thereby potentially reducing the risk of cancer.

## Why Each Wrong Option is Incorrect
- **Option A:** While certain metals and elements have been studied for their potential anticancer effects, without specifying, it's hard to directly refute. However, common metals like iron, zinc, and copper, though essential, are not primarily known for anticancer properties in their elemental form.
- **Option B:** Similarly, without specification, it's challenging to directly address. However, some elements might have roles in the body that are not primarily anticancer.
- **Option D:** This option seems to suggest a combination or another element. Without specifics, it's hard to address directly, but typically, selenium is noted for clear anticancer properties.

## Clinical Pearl / High-Yield Fact
A key point to remember is that **selenium** is often associated with anticancer effects, particularly noted in the context of prostate, lung, and colon cancers. It's also worth noting that while dietary supplements of selenium are explored for cancer prevention, the optimal intake level is narrow, as high doses can be toxic.

## Correct Answer: C. Selenium.