Identify all factors of 43.
A: {1, 2, 22, 43}
B: {1, 3, 43}
C: {1, 4, 10, 43}
D: {1, 43}
The correct answer is D: {1, 43}.
Factors are the numbers that divide evenly into a given number without leaving a remainder. In this case, 43 is a prime number and the only factors it has are 1 and itself. Thus, {1, 43} is the correct answer.