The shape of a protein is primarily determined by
a) type and sequence of amino acids
b) size
c) cell location

The best answer is A.

The shape of a protein is determined by its primary structure. The primary structure is the sequence of amino acids  in each polypeptide chain which make up a protein.

The sequence of amino acids is basically a list of amino acids that are linked to each other to form a chain which is known as a polypeptide chain.

The structure of the finished protein will depend largely on the first  (primary) chain of amino acids to be produced to make up that protein.

the organisms are not adapted to live in some communities or habitats.

the answer is lactic acid from anaerobic respiration. the acid in lactic acid is what creates sore and burning muscles. if you think about how acid burns that will give you a clue for questions like this.