The correct option is A ATP
The major source of energy to perform cellular functions such as exocytosis, endocytosis, movement, and transmission of nerve impulses is adenosine triphosphate.The Adenosine triphosphate (ATP) molecule is the nucleotide which is also known as the "molecular currency" of intracellular energy transfe, or we can say that ATP is able to store and transport chemical energy within the cells.