Thermometer Sensitivity and Range Steps:

• Sensitivity measures the smallest detectable temperature change, indicated by finer scale divisions.
• Compare divisions: Q has the smallest intervals, so highest sensitivity.
• Range measures the total temperature span, from lowest to highest mark.
• Compare spans: R covers the widest temperature extremes, so greatest range.

Why C is correct:

• Q's finest divisions maximize sensitivity, defined as the change in scale length per unit temperature change.

Why the others are wrong:

• A pairs P (coarser divisions, lower sensitivity) with R.
• B pairs R (wide range but coarse divisions, low sensitivity) with S.
• D pairs Q with S (narrower span than R, smaller range).

Final answer: C