Final Answer:
The pair of consecutive positive integers that are both prime numbers is A. 3 and 5.
Step-by-step explanation:
Prime numbers are integers greater than 1 that have no positive divisors other than 1 and themselves. To determine consecutive prime numbers among the options provided:
A. 3 and 5: Both 3 and 5 are consecutive positive integers and are prime numbers. 3 is divisible by 1 and 3 only, and 5 is divisible by 1 and 5 only, meeting the criteria of prime numbers and being consecutive.
B. 7 and 8: Although 7 is a prime number (divisible by 1 and 7 only), 8 is not prime as it is divisible by 1, 2, 4, and 8, breaking the condition of consecutive prime integers.
C. 2 and 3: Both 2 and 3 are prime numbers but not consecutive. While 2 is the only even prime number, it is not followed immediately by 3.
D. 1 and 2: 2 is a prime number, but 1 is not a prime number since it has only one positive divisor (1 itself), not meeting the criteria for prime numbers.
Hence, the only pair of consecutive positive integers that are both prime numbers among the given options is A. 3 and 5, as both numbers meet the criteria of being primes and are consecutive.