What distinguishes disruptive and directional selection pressures when both select for extreme genetic traits?

Yes both are different. In directional selection one of the extreme traits is favored, whereas in disruptive selection both the extreme traits are favored.

Explanation:

Directional: If selection acts to eliminate one extreme form and supports the other extreme then the peak shifts in the direction which is selected by the nature.

Disruptive: If the selection does not favor the mean character value, rather favors both the peripheral character values then this kind of selection is called disruptive selection.

the answer would be..

b. sucking