Line 1c as indicated is where dividends from Sch. B (form 1099-DIV) are inserted. Line 1f is the sum of 1a thru 1e. So line 1f will equal 1c if there is no other source of income.
Line 1k is the amount of qualified dividends reduced by the algorithm if required. It will be zero if no adjustment is required. The algorithm is described in the f1116 instructions on p. 8 under the heading "How to make adjustments."
