Which of the following statement are correct regarding short day plant (SDPs) ?

Options

A. they are apt to flower in the fall
B. they are the same as long as long day plants
C. they do not have a critical photoperiod
D. all of the above are correct

Answer

To solve the question regarding the correct statements about short day plants (SDPs), we will analyze each option provided.

### Step-by-Step Solution:

1. **Understand the Definition of Short Day Plants (SDPs)**:
- Short day plants are those that require a longer duration of darkness (night) than light (day) to initiate flowering. Typically, they flower when the day length is less than 12 hours.

2. **Evaluate Each Statement**:
- **Statement 1**: "They are apt to flower in the fall."
- This statement is **correct**. Short day plants often flower in the fall or spring when the days are shorter.

- **Statement 2**: "They are the same as long day plants."
- This statement is **incorrect**. Long day plants require longer daylight periods to flower, which is the opposite of short day plants.

- **Statement 3**: "They do not have a critical photo period."
- This statement is **incorrect**. Short day plants do have a critical photo period, but it is relatively short compared to long day plants. They need specific light conditions to flower.

- **Statement 4**: "All of the above are correct."
- Since not all statements are correct, this option is also **incorrect**.

3. **Conclusion**:
- The only correct statement regarding short day plants is that they are apt to flower in the fall. Therefore, the correct answer is **Option A**.

### Final Answer:
**Option A**: They are apt to flower in the fall.