Concept:
In comparison problems, we arrange elements using given inequalities. To find the heaviest, we need a complete or sufficient partial order.
Step 1: Analyze Statement I alone.
Given:
\[
D<B<E
\]
No information about A, C, F. Hence, cannot determine the heaviest.
Statement I alone is NOT sufficient.
Step 2: Analyze Statement II alone.
Given:
\[
D>A, C, F
\]
No comparison with B and E. Hence, cannot determine the heaviest.
Statement II alone is NOT sufficient.
Step 3: Combine both statements.
From I:
\[
D<B<E
\]
From II:
\[
D>A, C, F
\]
Combining:
\[
A, C, F<D<B<E
\]
Thus, E is the heaviest parcel.
Hence, both statements together are sufficient, but neither alone is sufficient.