The distilled alcohol like whiskey, rum, etc. are stronger than undistilled alcohol like champagne because
A)They are fermented products.
B)They are called distilled but are undistilled products.
C)Fermented product is further distilled to increase alcoholic concentration.
D)They are malted liquors.

Hint: Distilled spirit, often referred to as distilled liquor, is an alcoholic beverage (such as brandy, whiskey, rum, or arrack) produced by distillation from the first brewed wine or other fermented fruit or plant juice or from a starchy substance (such as separate grains).

Complete answer:
Distilled alcohol, often referred to as distilled spirits (such as brandy, whisky, rum), is obtained through wine or other fortified fruit or plant juice distillation or through first-brew starchy material distillation (such as different grains). The alcoholic content of distilled liquor is higher than that of beer, champagne or wine (undistilled alcohol). Distilled spirits are such alcoholic beverages that have boosted the ethyl alcohol content of the original fermented mixture by distillation.

Malt whiskey: made of at least 51 percent malted barley consisting of mash. Rye whiskey: made from a mash that contains at least 51% rye. Rye malt whiskey: made with at least 51 percent mash-made malted rye. Wheat whiskey: made from mash that contains at least 51% wheat.

Hence, the correct answer is option (C)

Note: When alcohol is heated to around 26 °C (79 °F) and if an ignition source is added to it, liquor that contains 40 per cent ABV (80 US proof) will catch fire. This temperature is referred to as the flashpoint. The pure alcohol flashpoint is 16.6 °C (61.9 °F), which is lower than the average room temperature.