Arising from placenta is megasporangium which is commonly known as :

Options

A. Ovule
B. Ovary
C. Ovarian cavity
D. Stamen

Answer

To solve the question "Arising from placenta is megasporangium which is commonly known as:", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Terms**:
- The term "megasporangium" refers to a structure that produces megaspores, which are involved in the formation of female gametes in plants.

2. **Identifying the Location**:
- In flowering plants, the megasporangium is located within the ovary, which is part of the female reproductive structure known as the gynoecium.

3. **Role of the Placenta**:
- The placenta is a tissue within the ovary that supports the ovules. It is from the placenta that the megasporangium arises.

4. **Common Name of Megasporangium**:
- The megasporangium is commonly referred to as the "ovule". This is the structure that develops into a seed after fertilization.

5. **Analyzing the Options**:
- The options given are: ovule, ovary, ovarian cavity, and stamen.
- Among these, the correct answer is "ovule" since it is the common name for the megasporangium.

### Final Answer:
The megasporangium, which arises from the placenta, is commonly known as **ovule**.

---