In Riccia, the female reproductive structures are called:

Options

A. Antheridium
B. Strobili
C. Archegonium
D. Oogonium

Answer

To solve the question "In Riccia, the female reproductive structures are called:", we will analyze the options provided and understand the reproductive structures of Riccia, which is a type of bryophyte.

### Step-by-Step Solution:

1. **Identify the Plant Group**: Riccia is a member of the bryophytes, which are non-vascular plants that include liverworts, mosses, and hornworts. They are often found in moist environments and depend on water for reproduction.

**Hint**: Remember that Riccia belongs to the bryophyte group, which includes liverworts.

2. **Understand Reproductive Structures**: In bryophytes, there are distinct male and female reproductive structures. The male reproductive structure is called antheridium, which produces male gametes (antherozoids).

**Hint**: Male reproductive structures in bryophytes are known as antheridia.

3. **Identify Female Reproductive Structure**: The female reproductive structure in bryophytes, including Riccia, is called archegonium. This structure is responsible for producing egg cells.

**Hint**: Look for the term that refers to the female reproductive organ in bryophytes.

4. **Evaluate the Options**:
- **Antheridium**: This is the male reproductive structure, so it is not correct.
- **Strobilae**: These refer to cone-like structures in some plants, not applicable here.
- **Archegonium**: This is indeed the female reproductive structure in Riccia.
- **Oogonium**: This term refers to a female reproductive structure found in some algae and fungi, not in bryophytes.

**Hint**: Eliminate options that do not pertain to the female reproductive structure in bryophytes.

5. **Conclusion**: The correct answer is archegonium, as it is the female reproductive structure in Riccia.

### Final Answer:
The female reproductive structures in Riccia are called **Archegonium**.