Concept:The place value of a digit after the decimal point is determined by its position.Explanation:In 42.7531, the digit 3 appears in the third place after the decimal point.The positions after the decimal are tenths, hundredths, thousandths, and so on.Since 3 is in the thousandths place, its value is 3×10001.Therefore, the value of 3 is 10003.Answer:10003, which is option B.