Classify the year 1900 correctly according to the Gregorian leap-year rule.

Correct answer: Option D — Ordinary year. 1900 is divisible by 4. Hence it is a ordinary year. Option A (Leap year) is rejected because it does not equal the computed result; it represents a counting, direction, leap-year, interval, or hand-motion error. Option B (Century year only) is rejected because it does not equal the computed result; it represents a counting, direction, leap-year, interval, or hand-motion error. Option C (Cannot be determined) is rejected because it does not equal the computed result; it represents a counting, direction, leap-year, interval, or hand-motion error.