According to Bernoulli’s equation for a perfect incompressible fluid flow which of the following relation is correct:where Z is the potential head, p is the pressure, w is the weight density, v is the velocity and g is acceleration due to gravity

• A. \(Z + \frac pw + \frac {v^2}{2g}= Constant \)
• B. \(Z + \frac pw - \frac {v^2}{2g}= Constant \)
• C. \(Z - \frac pw + \frac {v^2}{2g}= Constant \)
• D. \(Z -\frac pw - \frac {v^2}{2g}= Constant \)