To find the surface area of a conical hat, we can use the formula for the lateral surface area of a cone:
\[ \text{Lateral Surface Area} = \pi r l \]
where:
- \( r \) is the radius of the base of the cone,
- \( l \) is the slant height of the cone.
Given:
- The diameter of the hat is 38 cm, thus the radius \( r \) is half of that:
\[ r = \frac{38}{2} = 19 \text{ cm} \]
- The slant height \( l \) is 30 cm.
Substituting these values into the formula:
\[ \text{Lateral Surface Area} = 3.14 \times 19 \times 30 \]
Now calculate it step by step:
- Calculate \( 19 \times 30 \):
\[ 19 \times 30 = 570 \]
- Now multiply by \( \pi \) (which we've approximated as 3.14):
\[ \text{Lateral Surface Area} = 3.14 \times 570 = 1,791.80 \text{ square centimeters} \]
Thus, the surface area of the nón lá is approximately \( 1,791.80 \) square centimeters.
Since the provided options do not exactly match this calculated area, the closest approximate number is 1,789.8 square centimeters.
Therefore, the correct answer is:
1,789.8 square centimeters.