On which weekday did April 10, 1998 occur?

Correct answer: Option D — Friday. Counting total odd days up to this date, or using a verified Gregorian calendar calculation, gives weekday index 4 where Monday is 0; therefore the day is Friday. Option A (Saturday) is rejected because it does not equal the computed result; it represents a counting, direction, leap-year, interval, or hand-motion error. Option B (Sunday) is rejected because it does not equal the computed result; it represents a counting, direction, leap-year, interval, or hand-motion error. Option C (Tuesday) is rejected because it does not equal the computed result; it represents a counting, direction, leap-year, interval, or hand-motion error.