How similar are these two sentences, on a scale from 0-5 (0 is "not similar" and 5 is "very similar")?

U.S. and Turkey weigh no-fly zones for Syria
U.S. and Turkey Tighten Coordination on Syria

Available choices:
[a]. 0.
[b]. 1.
[c]. 2.
[d]. 3.
[e]. 4.
[f]. 5.
[c].