CREATE TABLE table_19931 ("Series Ep." TEXT, "Episode" FLOAT, "Segment A" TEXT, "Segment B" TEXT, "Segment C" TEXT, "Segment D" TEXT)

What are the titles of segment c for series episode is 21-08?
SELECT "Segment C" FROM table_19931 WHERE "Series Ep." = '21-08'
SELECT "Segment C" FROM "table_19931" WHERE "Series Ep." = '21-08'