Cryopreservation is the preservation of germplasm at very low temperatures of around
A. -121 °C
B. -196 °C
C. -0 °C
D. -101 °C

Hint: Cryopreservation is the method of state, change of biological material like germplasm at extraordinarily low temperatures. Cryopreservation could also be outlined because of the maintenance of biologics at sub-freezing temperatures, below −80°C and generally below −140°C.


Complete step by step solution:
Cryopreservation is preservation at −196 °C (liquid nitrogen). It will maintain tissue culture, embryos, animal cells/ tissues, and spermatozoa indefinitely.
The cryopreserved material is revived through special techniques once needed.
Cryo-preservation or cryo-conservation could be a method wherever organelles, cells, tissues, extracellular matrix, organs, or the other biological constructs at risk of harm caused by unregulated chemical mechanics are preserved by cooling to terribly low temperatures (typically −80 °C or −112 °F victimization solid dioxide dioxide °C (−321 °F) victimization liquid nitrogen).

Cryopreservation strategies ask to achieve low temperatures while not inflicting extra harm caused by the formation of ice crystals throughout state change.
New strategies are being investigated thanks to the inherent toxicity of the many cryoprotectants. Cryoconservation of animal genetic resources is finished with the intention of conservation of the breed.
Cryopreservation is the technique of keeping the live cells, tissues and different biological samples in an exceedingly deep freeze at subzero temperatures for the storage or preservation. The sample is often unbroken at −196°C.

Hence, option B is correct.

Note:
 ​Cryopreservation is when cells frozen in line with the protocols are unbroken for many years in atomic number 7. Ideally, frozen cells shouldn't be kept at -80 ºC for long periods of time (up to at least one week) and may be transferred into atomic number 7 whenever attainable.