CREATE TABLE table_19917 ("Series Ep." TEXT, "Episode" FLOAT, "Segment A" TEXT, "Segment B" TEXT, "Segment C" TEXT, "Segment D" TEXT)

Name the number of episods for segment c being s oyster
SELECT COUNT("Episode") FROM table_19917 WHERE "Segment C" = 's Oyster'
SELECT COUNT("Episode") FROM "table_19917" WHERE "Segment C" = 's Oyster'