Answer:
[tex](B) \dfrac12H (B+D)[/tex]
Step-by-step explanation:
[tex]\text{Area of a trapezoid }= \dfrac12 ($Sum of the parallel sides) \times $Height\\Parallel Sides = B and D\\Height =H\\Therefore:\\\text{Area of the trapezoid }= \dfrac12 (B+D) H[/tex]
The correct option is B.