Introduction:
The lowest part of a plant is the roots. The stem, on the other hand, bears the fruit, flower, and leaves. In this question, we are asked to identify the lowest part of the plant and the components that are borne by the stem.

Explanation:
To understand why the correct answer is option 'B' (Roots, Leaves), let's delve into the functions and characteristics of roots, stems, and their respective components.

1. Roots:
- Roots are the underground part of the plant that anchors it in the soil and absorbs water and nutrients.
- They are typically found below the surface of the soil, making them the lowest part of the plant.
- Roots do not bear fruit, flowers, or leaves directly.

2. Stem:
- The stem is the part of the plant that supports the branches, leaves, flowers, and fruits.
- It acts as a conduit, transporting water, nutrients, and sugars between the roots and other parts of the plant.
- The stem grows above the surface of the soil and can vary in length and thickness depending on the plant species.
- The stem bears fruit, flowers, and leaves.

3. Fruit:
- Fruits are the mature ovaries of flowering plants that contain seeds.
- They develop from the fertilized flower and are often eaten by animals, aiding in seed dispersal.
- Fruits can grow on different parts of the plant, including the stem.

4. Leaves:
- Leaves are the main site of photosynthesis in plants, converting sunlight, water, and carbon dioxide into energy-rich sugars.
- They are typically attached to the stem by a stalk called a petiole.
- Leaves can come in various shapes, sizes, and patterns, and they play a crucial role in the plant's overall growth and function.

Conclusion:
Based on the characteristics and functions of roots, stems, fruits, flowers, and leaves, we can conclude that the roots are the lowest part of the plant, while the stem bears the fruit, flower, and leaves. Therefore, the correct answer to the given question is option 'B' (Roots, Leaves).