Two particles are projected simultaneously from the level ground as shown in figure. They may collide after a time:

• A. \[\frac{x\sin {{\theta }_{2}}_{\,}}{{{u}_{1}}}\]
• B. \[\frac{x\text{ cos}{{\theta }_{2}}_{\,}}{{{u}_{2}}}\]
• C. \[\frac{x\sin {{\theta }_{2}}_{\,}}{{{u}_{1}}\sin \left( {{\theta }_{2}}-{{\theta }_{1}} \right)}\]
• D. \[\frac{x\sin {{\theta }_{1}}_{\,}}{{{u}_{2}}\sin \left( {{\theta }_{2}}-{{\theta }_{1}} \right)}\]