Question

what is the final step in ensuring the sketch is fully defined? applying dimensions adding color converting arcs to reference arcs using the trim tool

Explanation:

To fully define a sketch (e.g., in CAD software), dimensions are applied to specify lengths, angles, etc., which fixes the geometry. Adding color, converting arcs to reference arcs, or using the trim tool don't define the sketch's geometric parameters. So the correct step is applying dimensions.

Answer:

A. Applying dimensions