Shamar lowers himself into a hot bath. At first, he can barely stand the scalding-hot water; gradually, though, he gets used to the temperature and is able to sit comfortably in the tub. Shamar's experience illustrates sensory:

Answer

Adaptation,

Explanation:

The set of characteristic an organism exhibit in order to survive in an environment is called adaptation. This may be changes in physical characteristic or adjustment in  the usual behaviour.

Generally for an organims to survive in his habitat  adaptation is important.It is usually due to interaction of the effects of environments with the genotype and phenotype  of the organism. Thus mutation which gives variation is the factor which makes  organism to  adjust to the habitat. Therefore adaptation of organism to the habitat  is dictated by the  selective pressure in the habitat.  And this is passed down to subsequent generation.

Thus Shamar sensory cells gained adaptation with time, and she was able to sit comfortably in the tub. The behavioural and physical changes she demonstrated at onset  were the necessary changes needed to adapt.

Generally it can be physiological, behavioural, physical or structural depending on the  need to adjust to the habitat.