Question: Which soft drink, Diet Rite or Julmust, is popular in Sweden during Christmas?

Context paragraphs:
Harry Roberts (inventor): Harry Roberts is the co-inventor of julmust and co-founder of Roberts AB in Örebro in 1910, Sweden.  After studying chemistry in Germany during the late 19th century he invented the soft drink together with his father Robert Roberts.

Piscola: Piscola or Combinado Nacional (national mix) is a highball cocktail, made of pisco and most commonly a cola drink, that is popular in Chile.  A piscola may be "black" or "white" depending if it is mixed with a cola or ginger ale, Tonic, Sprite or a similar soft drink.  The drink is prepared by filling a highball glass with ice and then adding pisco followed by the soft drink in a proportion ranging from 1:1 to 1:3.  Sometimes slices of lemon or key lime may be added.  In Chile, February 8 has been celebrated as the "day of the piscola" since 2003.

Diet Rite: Diet Rite is a brand of no-calorie soft drinks originally distributed by the RC Cola company.

Patio (soda): Patio Diet Cola was a brand of diet soda introduced by Pepsi in 1963.  It was created in response to Diet Rite Cola.  Fitness promoter Debbie Drake was Patio Diet Cola's spokesperson; the drink was also marketed as a soda alternative for diabetics.

Urge (drink): Urge is a citrus flavored soft drink produced by Coca-Cola Norway that was first introduced in the country in 1996, and later on was released in Denmark and Sweden.  It is the predecessor of the American soft drink Surge, which was introduced in the USA in 1997.  Urge was discontinued in Denmark and Sweden in 2001.  In Norway, Urge sales increased greatly over the years reaching a market share near 10% despite receiving no marketing since its initial launch.

Nichols plc: Nichols plc, based in Newton-le-Willows, Merseyside, England, is a company well known for its lead brand Vimto, a fruit flavoured cordial.  The company can trace its roots back to the invention of Vimto, by John Noel Nichols in 1908.  Today the company operates two types of businesses, firstly the sale of Vimto and other brands (such as Panda Pops, which Nichols acquired from Hall & Woodhouse in 2005) via supermarkets and associated outlets throughout the world and secondly its soft drink dispense operation in the UK.  The soft drink operation is handled under the name of Cabana and is the UK's largest independent supplier of dispensed soft drinks.  Due to its success of the Vimto soft drink, Nichols plc started selling Vimto chews and Vimto chew bars.

Julmust: Julmust (Swedish: "jul" "Yule" and "must " "not yet fermented juice of fruit or berries", though there is no such juice in "julmust") is a soft drink that is mainly consumed in Sweden around Christmas.  During the other part of the year it is usually quite difficult to find in stores, but sometimes it is sold at other times of the year under the name "must".  At Easter the name is påskmust (from "påsk ", "Easter" / "Paschal" ["q.v."]).  The content is the same regardless of the marketing name, although the length of time it is stored before bottling differs; however, the beverage is more closely associated with Christmas, somewhat less with Easter and traditionally not at all with the summer.  45 million litres of "julmust" are consumed during December, which is around 50% of the total soft drink volume in December and 75% of the total yearly must sales.

Roberts AB: Roberts AB is the company that makes the syrup for the traditional Swedish drink julmust.  The company was founded in 1910 by Harry Roberts and his father Robert Roberts (who died in 1932).  The company is located in Örebro, Sweden and currently has 15 employees.  The current owner is Göran Roberts, a grandson of Harry.  They do not produce their own soft drinks, just the syrup.  Apart from julmust they also make syrup for cola, various fruit drinks and Champis.

Diet Pepsi: Diet Pepsi and Diet Pepsi Classic Formula Blend (stylized as diet PEPSI CLASSIC SWEETENER BLEND) are no-calorie carbonated cola soft drinks produced by PepsiCo, introduced in 1964 as a variant of Pepsi-Cola with no sugar.  First test marketed in 1963 under the name Patio Diet Cola, it was re-branded as "Diet Pepsi" the following year, becoming the first diet cola to be distributed on a national scale in the United States.  In the 1960s and 1970s its competition consisted of Tab, produced by The Coca-Cola Company, and Diet Rite soda, produced by Royal Crown.  Diet Coke was a later entrant to the diet cola market; though shortly after entering production in 1982 it became the primary competing diet cola to Diet Pepsi.

Goombay Punch: Bahamas Goombay Punch is a soft drink that is produced in the Bahamas.  It is very sweet and has a high sugar content.  Goombay Punch is widely available throughout the bahamas in 12 fl oz cans as well as 20 fl oz bottles.  6-packs of the soft drink are also widely available.  The soft drink comes in two varieties, Bahamas Goombay Punch (the stock flavor) and Goombay Fruit Champagne.  The regular flavor is yellow in color (see picture).

Supporting paragraphs: Diet Rite Julmust
Answer: Julmust