To solve the problem, we need to determine the volume of a sphere given its diameter \( d \). Let us analyze this step by step.
1. Formula for the Volume of a Sphere:
The standard formula for the volume \( V \) of a sphere in terms of its radius \( r \) is:
$$ V = \frac{4}{3} \pi r^3 $$
2. Relating Diameter and Radius:
The diameter \( d \) of a sphere is twice its radius \( r \). Therefore:
$$ d = 2r $$
Solving for \( r \):
$$ r = \frac{d}{2} $$
3. Substituting \( r \) in the Volume Formula:
We substitute \( r = \frac{d}{2} \) into the volume formula:
$$ V = \frac{4}{3} \pi \left( \frac{d}{2} \right)^3 $$
Now, simplify the expression:
$$ V = \frac{4}{3} \pi \left( \frac{d^3}{8} \right) $$
$$ V = \frac{4}{3} \cdot \frac{1}{8} \pi d^3 $$
$$ V = \frac{4}{24} \pi d^3 $$
$$ V = \frac{1}{6} \pi d^3 $$
4. Conclusion:
The volume of the sphere in terms of its diameter \( d \) is \( \frac{1}{6} \pi d^3 \).
Final Answer:
The correct option is \( {\frac{1}{6} \pi d^3} \).