Explanation:

- To find the total surface area of a closed hemisphere, we calculate:

- Curved surface area of the hemisphere: $2\pi r^2$

- Area of the base circle: $\pi r^2$

- First, calculate the radius from the diameter: The diameter is 7 cm, so the radius is $7/2=3.5$ cm.

- Total surface area = $2\pi r^2+\pi r^2=3\pi r^2$

- Substituting the radius:

$=3\times \frac{22}{7}\times (3.5{)}^2$

$=3\times \frac{22}{7}\times 12.25$

$=3\times 38.5$

$=115.5$ cm${}^2$

- The correct option is:

- Option 4, 115.5 cm${}^2$