Answer:
Volume of the rock=
![V=(1)/(3) (17)(12)](https://img.qammunity.org/2021/formulas/mathematics/high-school/ckdwc7jzipdmxu9ap5jw12uhas36hbbeno.png)
Explanation:
Volume of triangular pyramid =
![(1)/(3) BH](https://img.qammunity.org/2021/formulas/mathematics/high-school/j83dh4omoovlu2p2ekprfwnw5u8h8urlkx.png)
Where B is the area of base
H is the height of pyramid
Length if base of base triangle = 8.5 inches
Height of base = 4 inches
Area of base triangle =
![(1)/(2) * base * height = (1)/(2) * 8.5 * 4=17 inches^2](https://img.qammunity.org/2021/formulas/mathematics/high-school/r6hj8vkncjyoh3lqxstto35v36b8elufx5.png)
Height of pyramid = 12 inches
Volume of triangular pyramid =
![(1)/(3) BH=(1)/(3) (17)(12)](https://img.qammunity.org/2021/formulas/mathematics/high-school/mwtflkccyd4m6zps1z241dgsrpctk6ngil.png)
So, option D is true
Volume of the rock=
![V=(1)/(3) (17)(12)](https://img.qammunity.org/2021/formulas/mathematics/high-school/ckdwc7jzipdmxu9ap5jw12uhas36hbbeno.png)