**Core Concept**
Iron is an essential micronutrient required for various bodily functions, including oxygen transport and DNA synthesis. It is primarily obtained through dietary sources, with heme and non-heme iron being the two main forms. Heme iron is found in animal-based foods, while non-heme iron is found in plant-based foods.

**Why the Correct Answer is Right**
Non-heme iron is commonly found in plant-based foods like beans, lentils, and fortified cereals. However, the bioavailability of non-heme iron is lower compared to heme iron, which is found in animal-based foods like red meat, poultry, and fish. This is because heme iron is more easily absorbed by the body.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it is a good source of heme iron, which is more easily absorbed by the body.
* **Option B:** This option is incorrect because it is a good source of non-heme iron, which is commonly found in plant-based foods.
* **Option C:** This option is incorrect because it is a good source of heme iron, which is more easily absorbed by the body.

**Clinical Pearl / High-Yield Fact**
It is essential to consume vitamin C-rich foods along with non-heme iron sources to enhance its absorption. Examples of vitamin C-rich foods include citrus fruits, bell peppers, and tomatoes.

**Correct Answer: D. Olive Oil.**