Which of these cocktails does NOT use Vodka?

The Regular Rob Roy is a variation of the classic Rob Roy cocktail, which is made with whiskey, typically Scotch, rather than vodka. The primary ingredients of a Rob Roy include whiskey, sweet vermouth, and Angostura bitters, establishing it firmly as a whiskey-based drink. This distinguishes it from the other options presented, which all incorporate vodka as a key ingredient.

In contrast, both the French Martini and Watermelon Martini are well-known vodka cocktails. The French Martini typically combines vodka, raspberry liqueur, and pineapple juice, while the Watermelon Martini features vodka alongside fresh watermelon juice and possibly additional ingredients for flavor. The cocktail option referred to here is also likely to pertain to a general mixed drink that includes vodka as a common base spirit, further reinforcing the distinction from the Regular Rob Roy.