11.Minimal

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In this context, minimal means that the set of columns (attributes) chosen to uniquely identify a row contains no unnecessary parts—if you remove any column from that set, 
it would no longer uniquely identify the row.

Breaking It Down with an Example
Imagine a table with columns A, B, and C where:

The combination (A, B, C) uniquely identifies each row.
However, if it turns out that (A, B) alone is enough to uniquely identify each row, then (A, B, C) is not minimal because C is extra.
Thus, the minimal key here is (A, B) since you cannot remove A or B without losing the ability to uniquely identify the row. This minimal set is what we call a candidate key.

One-Line Definition Recap
Minimal (in this context): A set of columns that is just sufficient to uniquely identify a row—removing any column would break this uniqueness.