What is the formula for the helix angle?

• A. Φ=tan-1\(\frac {V_0}{V_E}\)
• B. Φ=sin-1\(\frac {V_0}{V_E}\)
• C. Φ=cos-1\(\frac {V_0}{V_E}\)
• D. Φ=tan-1\(\frac {V_E}{V_0}\)