Arising from the placenta are the megasporangia, commonly called:

Options

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

Answer

To answer the question "Arising from the placenta are the megasporangia, commonly called:", we will follow these steps:

### Step 1: Understand the Terms
- **Placenta**: In the context of flowering plants, the placenta is the tissue within the ovary that attaches the ovules to the ovary wall.
- **Megasporangia**: These are structures that produce megaspores, which develop into female gametophytes.

### Step 2: Identify the Correct Term
- The question asks for what the megasporangia are commonly called when they arise from the placenta. In flowering plants, the megasporangia are specifically referred to as **ovules**.

### Step 3: Analyze the Options
- **Ovary**: This is the part of the flower that contains the ovules and develops into fruit after fertilization.
- **Ovarian cavity**: This is the space within the ovary where the ovules are located, but it is not the term for the megasporangia themselves.
- **Stamen**: This is the male reproductive part of the flower and does not relate to megasporangia.

### Step 4: Conclusion
Based on the definitions and analysis, the correct answer to the question is **ovule**. The megasporangia are commonly called ovules, which arise from the placenta in the ovary.

### Final Answer
**Ovule**

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