While making a tapering branch with a round brush the stroke suddenly becomes thick at the end. Which control failed?

Correct answer: Pressure increased instead of decreasing at the end

A taper is governed mainly by gradual pressure control. A round brush spreads its bristles and deposits a wider mark when the hand presses harder; releasing pressure narrows the bristles and produces a fine branch tip. Since the stroke became thick at the end, the pressure must have increased or failed to release, making option C correct. Colour choice, paper choice and a clean brush do not directly determine this sudden change in width.