Answer:
c. it has a low conductivity coefficient
Step-by-step explanation:
The conductivity coefficient indicates the ease through which heat can be transferred in a material.
Heat flux is given by

Where, 
k = Thermal conductivity coefficient
 = Gradient in temperature
 = Gradient in temperature
The thermal conductivity of blubber is 0.25 W/mK while the thermal conductivity of air is 0.02435 W/mK.
It can be seen that air has a lower thermal conductivity coefficient hence, sea otters can survive better if they use air instead of blubber.