Final answer:
The answer to the question is that C. b is a positive integer must be true, as dividing a number by its prime factors results in a positive integer. The other options cannot be determined as true without additional information.
Step-by-step explanation:
The student is asking a question related to number theory and divisibility rules involving prime numbers. We have three distinct positive integers a, p, and q where p and q are prime, and a is divisible by both p and q. The value of b is given as a/(p*q).
Based on this information, we can confidently determine that C. b is a positive integer must be true. This is because when a positive integer that is divisible by two primes is divided by the product of those primes, the result is also a positive integer, assuming that the primes are factors of the integer.
Regarding options A and B:
- Option A: We cannot be sure without additional context because b could have more factors than just p and q.
- Option B: This is generally true but with the condition that r is not a multiple of either p or q. If r is a multiple of p or q, then a may not be divisible by r depending on the multiplicity of p and q in a.