Adults = \(\frac{17}{20}\) of spectators, so children = \(1 - \frac{17}{20} = \frac{3}{20}\).<br><br>Boys : Girls = 4 : 1, so boys = \(\frac{4}{5}\) of the children.<br><br>&bull; Fraction of spectators who are boys = \(\frac{3}{20} \times \frac{4}{5} = \frac{12}{100}\)<br>&bull; As a percentage: 12%<br><br>Option A is 12%.<br><br>Final Answer: A: 12%