To convert 0.80 to a fraction, we can follow these steps:
- Write 0.80 as \(\frac{80}{100}\) because the decimal has two digits.
- Simplify \(\frac{80}{100}\) by finding the greatest common divisor (GCD) of 80 and 100, which is 20.
- Divide both the numerator and the denominator by their GCD:
\[ \frac{80 \div 20}{100 \div 20} = \frac{4}{5} \]
Thus, 0.80 as a fraction in simplest form is \(\frac{4}{5}\).
The correct answer is C: \(\frac{4}{5}\).