Duplet and octet configuration differs in terms of:

The correct options are
A Number of electrons in outermost shell
C Number of Shells
Duplet and octet configuration differs in terms of:

1) Number of electrons in outermost shell: The atom of an element having duplet configuration has only two electrons in the outermost shell, whereas the atom of an element having octet configuration has 8 electrons in its outermost shell.

2) Number of shells: The atom of an element having duplet configuration has only 1 shell i.e. K-shell, whereas the atom of an element having octet configuration has more than 1 shell (K, L, M, N,.....).