Which of the following statements about 'fission' is correct ?
1. It is related with the creation of new individuals by means of cell division in unicellular organism.
2. It is related with the transformation of heavier nuclei into smaller nuclei.
3. It is related with the creation of a heavier nuclei by means of combining two higher nuclei.
Select the correct answer using the code given below :

Options

A. 1 only
B. 2 only
C. 1 and 2 only
D. 1 and 3 only