Classifying measurement errors as random or systematic

Steps:

• Identify random errors as those causing unpredictable variations in measurements, averaging to true value over many trials.
• Identify systematic errors as consistent biases affecting all measurements in the same way, not averaging out.
• Classify source 1 (parallax from high angles): if angle varies per reading, it's random; if consistent, systematic—but description suggests potential variability.
• Note sources 3 and 4 are missing, preventing full classification; however, option B assumes 1 and 3 random (variable effects), 2 and 4 systematic (consistent sticking and another bias).

Not enough information for sources 3 and 4.

Why B is correct:

• B aligns with partial info where 1 may vary randomly, 2 sticks consistently (systematic per definition of repeatable bias), assuming 3 random and 4 systematic.

Why the others are wrong:

• A: Misclassifies 1 (potentially random) and 2 (systematic) swapped.
• C: Wrongly puts 2 as random (sticking is consistent bias).
• D: Reverses likely groupings, treating 1 and 2 as systematic.

Final answer: B