Concept:Use cosecθ=sinθ1 and find angles in [0,2π) where sinθ is negative.Explanation:Given: cosecθ=−2.Since cosecθ=sinθ1, we get sinθ=−21.sinθ is negative in the third and fourth quadrants.The reference angle for sinθ=21 is 6π.In the third quadrant: θ=π+6π=67π.In the fourth quadrant: θ=2π−6π=611π.Thus, the principal solutions are 67π and 611π.Answer:Option C: 67π,611π