Which common error makes a tall bottle appear wider than it actually is?

Correct answer: Measuring height and width without comparing their ratio

Accurate observation depends on comparing dimensions rather than judging each measurement in isolation. If the height-to-width ratio is not checked, the artist may draw the bottle too broad or too short. Thus, option A is correct. A central axis, light construction lines, and observing negative space are helpful methods that reduce proportion errors rather than cause them.