Final answer:
Lacy's number, which is a factor of 30 and also a composite number, can either be 30 or 15 since both satisfy the given conditions.
Step-by-step explanation:
The question asks which of the given numbers is both a factor of 30 and a composite number. A composite number is a positive integer that has at least one divisor other than 1 and itself. Examining the options: A. 30 is a factor of itself and is composite, B. 15 is a factor of 30 and is composite, C. 5 is a factor of 30 but it is not composite (it's prime), and D. 8 is not a factor of 30. Therefore, the possible numbers Lacy might be thinking of, that are factors of 30 and composite, are 30 and 15.