Answer: Third option is correct.
Step-by-step explanation:
Since we have given that
Height of trapezium = 3 units
and Length of parallel sides are 5 units ad 4+4=8 units.
So, Area of trapezium is given by
[tex]\dfrac{1}{2}\times \text{Sum of parallel sides}\times height\\\\=\dfrac{1}{2}\times (5+8)\times 3\\\\=\dfrac{1}{2}\times 13\times 3\\\\=19.5\ sq.\ units[/tex]
So, we have given that "Volume of prism = 234 cubic units":
[tex]\text{Volume of prism}=\text{Area of base}\times height\\\\234=2\times \text{Area of trapezium}\times height\\\\234=2\times 19.5\times height\\\\234=39\times height\\\\height=\dfrac{234}{39}\\\\height=6\ units[/tex]
Hence, height of prism should be 6 units.
Thus, Third option is correct.