Q.Cryopreservation means it is a process to preserve plant cells, tissues or organs

Step 1. The chapter defines cryopreservation as cooling protoplasts, cells, tissues or organs to a very low temperature of -196 degC using liquid nitrogen, so that all enzymatic and chemical activity stops.

Step 2. Option (a) is wrong on two counts: ether is not the cooling medium, and it does not specify the correct extreme-low-temperature regime.

Step 3. Option (b) is wrong because cryopreservation uses a very LOW temperature, not a very high one.

Step 4. Option (d) states the correct medium (liquid nitrogen) and the correct general direction (very low temperature) but omits the specific -196 degC figure the chapter states, making option (c) the more complete and precise match to the text. …

Recall the exact cryopreservation temperature (-196 degC) and cooling medium (liqui …

• Confusing cryopreservation with a high-temperature or ether-based preservation method.
• Picking the vaguer 'very low temperature' option without the specific -196 degC figure over the fully precise option. …