Question

sorrow means :
problem solving that involves numbers or quantities
creating alliances to check the expansion of a hostile
power
careful consideration
something that causes great unhappiness

Explanation:

The word "sorrow" is related to emotions. Among the options, "something that causes great unhappiness" is the only one that pertains to an emotional state. The other options are about problem - solving (mathematics - related), political actions (social science - related), and a general cognitive process (not directly related to the emotional meaning of "sorrow").

Answer:

something that causes great unhappiness