Coefficient of Variation of Portfolio Returns

During a recent performance evaluation, an investment manager analyzed the returns of three different portfolios over a year. The portfolio returns were as follows:

Portfolio A: 8%, 10%, 12%, 9%, 11%
Portfolio B: 6%, 7%, 8%, 7%, 7%
Portfolio C: 10%, 20%, 0%, 10%, 10%

The manager wants to assess the variability of these portfolios' returns using the coefficient of variation (CV), which is defined as the ratio of the standard deviation to the mean, expressed as a percentage:

$$ CV = rac{ ext{Standard Deviation}}{ ext{Mean}} imes 100 $$

Which portfolio exhibits the highest coefficient of variation, indicating the greatest relative dispersion of returns?