The suitable temperature for stratification of apple seeds is:

Correct option is B

Stratification is a method of treating seeds to simulate natural conditions that they must experience before germination can occur. For apple seeds, stratification is essential because they exhibit deep seed dormancy.
Key Points:
· The suitable temperature for stratification of apple seeds is between 1°C to 5°C.
· This cold, moist treatment helps to break the physiological dormancy of seeds.
· The seeds are typically:
· Mixed with moist sand or peat moss.
· Placed in a refrigerator or cold room at 1–5°C.
· Left for a period of 60 to 90 days (depending on the species and variety).
· After stratification, the seeds become ready to germinate when sown under suitable conditions.
Other Options Explained:
· (a) Less than 0°C: Freezing temperatures can damage the seeds and are not suitable for stratification.
· (c) 7 – 10°C: Higher than the optimal range; may not effectively break dormancy.
· (d) 10 – 13°C: Too warm for cold stratification; seeds may remain dormant.