Answer:
LM could be a line segment if there is a bar over it (no arrows)
JK could be a line segment if there is a bar over it (no arrows)
JN could be a line segment if there is a bar over it (no arrows)
Explanation:
If there are arrows above any of the letters they are lines or rays
↔ means a line
→ means a ray
__ means a line segment
LM could be a line segment if there is a bar over it (no arrows)
JK could be a line segment if there is a bar over it (no arrows)
MK is not a because the are not connect directly with a line but an angle
JN could be a line segment if there is a bar over it (no arrows)