Final answer:
The correct answer is option a, the divisor is a decimal since it contains digits to the right of the decimal point. Whole numbers lack decimal places, and while fractions can represent decimals.
Step-by-step explanation:
When dividing 17.9 by 2.38, this operation clearly indicates that the divisor, 2.38, is not a whole number but a decimal value because it contains digits to the right of the decimal point. To further clarify, a whole number would not have any digits beyond the decimal point, and fractions are typically represented as a ratio of two integers (although decimal numbers can also be expressed as fractions). Understanding these basic mathematics principles is crucial in identifying number types and in performing arithmetic operations with a correct approach to significant figures and rounding.
When we perform the division, we get a result of approximately 7.53781512605042, which contains decimal places. This further confirms that the divisor is a decimal.