Rate the similarity of the following two sentences on a scale from 0 to 5, where 0 is "no meaning overlap" and 5 is "means the same thing"?

this further aggravated the situation.
north korea should not act further to aggravate the situation.

Select from the following.
(a). 0.
(b). 1.
(c). 2.
(d). 3.
(e). 4.
(f). 5.
(c).