Traffic intensity in a queuing system is indicated by

• A. \(\frac{{arrival~rate}}{{service~rate}}\)
• B. \(\frac{{serive~rate}}{{arrival~rate}}\)
• C. \(\frac{{arrival~rate}}{{service~rate\;-\;arrival~rate}}\)
• D. \(arrival\;rate\;\times\;service\;rate\)