From the point of view of MI N, there is a character distance between I and n, so judging I should be an intersection symbol ∩ a typographical error belonging to the topic.

That is: m ∩ n ≠ φ, the intersection of set m and set n is not an empty set, in other words, some elements of m and n are the same.

Solution: m = {x |- 1

n = { x | x-k & lt； =0}

= { x | x & lt=k}

∫M∩N≠φ

∴k>； =- 1

Choose B.