The angle between the two lines lx + my + n = 0 and l’x + m’y + n’ = 0 is given by tan-1 θ. What is θ equal to?

• A. \(\left| {\frac{{lm' - l{\rm{'}}m}}{{ll' - mm{\rm{'}}}}} \right|\)
• B. \(\left| {\frac{{lm' + l{\rm{'}}m}}{{ll' + mm{\rm{'}}}}} \right|\)
• C. \(\left| {\frac{{lm' - l{\rm{'}}m}}{{ll' + {\rm{\;}}mm{\rm{'}}}}} \right|\)
• D. \(\left| {\frac{{lm' + l{\rm{'}}m}}{{ll' - mm{\rm{'}}}}} \right|\)