To divide fractions, you multiply by the reciprocal of the divisor. So, to find \( \frac{5}{31} \div \frac{15}{23} \), you multiply \( \frac{5}{31} \) by the reciprocal of \( \frac{15}{23} \):
\[ \frac{5}{31} \div \frac{15}{23} = \frac{5}{31} \times \frac{23}{15} \]
Now, multiply the fractions:
\[ \frac{5 \times 23}{31 \times 15} = \frac{115}{465} \]
Next, we reduce the fraction \( \frac{115}{465} \). To do this, we find the greatest common divisor (GCD) of 115 and 465.
The prime factorization of 115 is \( 5 \times 23 \), and for 465, we factor it as follows:
- Divide by 5: \( 465 \div 5 = 93 \)
- Factor 93: \( 93 = 3 \times 31 \)
Thus, \( 465 = 5 \times 3 \times 31 \).
Now, we see the common factor:
- The GCD of \( 115 \) and \( 465 \) is \( 5 \).
Now, divide both the numerator and the denominator by \( 5 \):
\[ \frac{115 \div 5}{465 \div 5} = \frac{23}{93} \]
Therefore, the reduced form of \( \frac{115}{465} \) is \( \frac{23}{93} \).
Thus, the answer is:
D) \( \frac{23}{93} \)