$\pi$ is a partition of A if
- $|A_i| \geq 1$
- $A_i \cap A_j = \phi \ \forall A_i,A_j \in \pi$
- $\bigcup A_i = A$
Only option B is satisfying all the properties of a partition set.
In option A, $100$ is common in both sets
In option C, $100$ is missing in both the sets
In option D, $100$ is missing in both the sets