Let E = k^2+k-2 = (k-1)(k+2)

for E>0 means k-1 and k+2 have to be of same sign...ie either both positive or both negative.

Case 1. Both k-1 and k+2 are positive

k-1>0 , or k>1

and

k+2>0 or K<-2

Case 2. Both k-1 and k+2 are negative

k-1<0 , or k<1

and

k+2<0 or K>-2

Now look at the question stem.

A. k<1

If E>0 , we need more info.......so A is insufficient.

B. k>-2

If E>0 , we need more info.......so B is insufficient.

taking both A and B , it boils down to Case 2.

Therefore answer is C.

- ash

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ash

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I'm crossing the bridge.........