Answer:
The Latin prefix <em>semi-</em> means half.
Explanation:
If you look at the common, or shared traits of these words, you can see that all of them share one similar trait - being halved. Semicircle - half of a circle. Semifinal - test halfway through the year. Semisolid - Not liquid, but not solid either; about halfway in between.
Therefore, you can conclude that the Latin prefix <em>semi- </em>means <u><em>B.) Half</em></u>.
<em>Hope this helps! Good luck!</em>