Calculate the radius

The radius is half of the diameter: $r = d / 2 = 78 / 2 = 39 \text{ m}$.

$r = 39 \text{ m}$

Calculate the base area and curved surface area

The area to be painted is the interior base plus the interior wall area: $\text{Area} = \pi r^2 + 2\pi rh$.

$\text{Area} = \pi r(r + 2h)$

Substitute the values and compute

Substitute $r = 39$, $h = 79$, and $\pi = 22/7$ into the formula: $\text{Area} = \frac{22}{7} \times 39 \times (39 + 2 \times 79) = \frac{22}{7} \times 39 \times (39 + 158) = \frac{22}{7} \times 39 \times 197$.

$\text{Area} = \frac{22 \times 39 \times 197}{7} = \frac{169014}{7} \approx 24144.857...$

Final verification

Recalculating with higher precision or verifying against options, $24144.857$ rounds to $24144.9$, but the closest option provided is D ($24146.6$). Note: Exact calculation $\frac{169014}{7} \approx 24144.86$.

$\text{Area} \approx 24144.9 \text{ m}^2$