Question: Wenger is a company that creates the types of knives that were first used after what period?

Context paragraphs:
Murphy Knives: Murphy Knives was a knife manufacturing company founded by custom knife maker David "Dave" Zephaniah Murphy.  Murphy was best known as the original supplier of knives to the Gerber Legendary Blade Knife Company in 1938.  Murphy's knives had a distinctive aluminum handle which was later used on many thousands of Gerber knives.  Between 1941 and 1954 Murphy made approximately 90,000 Murphy Combat knives for troops to use in World War II.  These knives were marked on the handle Murphy Combat with USA on the obverse side.  They were made for servicemen during and after World War II.  These knives are now collectible by military knife collectors and are scarce despite the large number made.

W. R. Case &amp; Sons Cutlery Co.: W.R. Case & Sons Cutlery Company is an American manufacturer of traditional pocket knives, fixed blades/sporting knives, limited edition commemoratives and collectibles.  The company originated in Little Valley, New York, around the turn of the 20th century, before relocating to its current home, Bradford, Pennsylvania, in 1905.  The company's namesake, William Russell Case, first made knives with his brothers under the name, Case Brothers Cutlery Company.  His son, John Russell ("Russ") Case, worked as a salesman for his father's company before founding W.R. Case & Sons.

Mad Dog Knives: Mad Dog Knives was a custom knifemaking facility headed by Kevin McClung, a former Senior Materials Scientist at the American Rocket Company, Mad Dog Knives is based in Prescott, Arizona.  Mad Dog Knives made the fixed-blade knife known as the ATAK, used by Naval Special Warfare Groups 1 and 2 after the "SEAL Trials" of 1992.  Mad Dog Knives are typically made from selectively tempered, hand ground O1 Tool Steel with a hardchrome plating to protect the blade.

Cutting board: A cutting board is a durable board on which to place material for cutting.  The kitchen cutting board is commonly used in preparing food; other types exist for cutting raw materials such as leather or plastic.  Kitchen cutting boards are often made of wood or plastic and come in various widths and sizes.  There are also cutting boards made of glass, steel, or marble, which are easier to clean than wooden or plastic ones such as nylon or corian, but tend to damage knives due to their hardness.  Rough cutting edges—such as serrated knives—abrade and damage a cutting surface more rapidly than do smooth cutting implements.

A.G. Russell: A.G. Russell (August 27, 1933) was born in Eudora, Arkansas where his great-grandfather taught him how to make knives when he was nine.  Russell went on to make knives as a hobby and profession.  In 1964, Russell switched his focus to selling Arkansas whetstones and a year later began selling knives.  In 1968 he started the first forum for selling aftermarket knives, the A.G. Russell List of Knives for Immediate Delivery, which later became The Cutting Edge.  His mailing list was used as a basis for the first two knife magazines, "Knife World" and "The American Blade", now known as "Blade".  In 1970 he co-founded the Knife Collectors Club and the Knifemakers' Guild, both of which are the oldest continuously functioning organizations of their types.

Grapefruit knife: A grapefruit knife is a special type of knife designed specifically for cutting grapefruit.  Grapefruit knives are small with a curved serrated blade, designed to hug the curves of the grapefruit.  This is used to separate the outer edge of the segments from the rim of the fruit.  The term "grapefruit knife" can refer to a type of knife with short, serrated twin blades about 2mm apart, used to separate the sides of each section from the dividing membrane.  Some grapefruit knives incorporate both types, a double-sided curved blade on one side and the parallel twin blades on the other.  Another type includes an angled tip and double sided serrated blade.  When both types are used, the result is an intact-looking fruit with sections which lift out easily - especially if a "grapefruit spoon" is used.

Swiss Army knife: The Swiss Army knife is a pocketknife or multi-tool manufactured by Victorinox AG (and up to 2005 also by Wenger SA).  The term "Swiss Army knife" was coined by American soldiers after World War II due to the difficulty they had in pronouncing "Offiziersmesser", the German name.

Knife: A knife (plural knives) is a tool with a cutting edge or blade, hand-held or otherwise, with most having a handle.  Some types of knives are used as utensils, including knives used at the dining table (e.g., butter knives and steak knives) and knives used in the kitchen (e.g., paring knife, bread knife, cleaver).  Many types of knives are used as tools, such as the combat knife carried by soldiers, the pocket knife carried by hikers and the hunting knife used by hunters.  Knives are also used as a traditional or religious implement, such as the kirpan.  Some types of knives are used as weapons, such as daggers or switchblades.  Some types of knives are used as sports equipment (e.g., throwing knives).  Knives are also used in agriculture, food harvesting etc.; the sickle, the scythe and even the combine harvester are knives.

Victorinox: Victorinox ( ) is a knife manufacturer based in the town of Ibach, in the Canton of Schwyz, Switzerland.  It is well known for its Swiss Army knives.  The Swiss Army knives made by Victorinox are made of Swedish steel from Sandvik.  Since its acquisition of rival Wenger in 2005, it has become the sole supplier of multi-purpose knives to the Swiss army.  It is the biggest manufacturer of pocket knives in the world; in addition, the company licenses its logo for watches, apparel, and travel gear.

Wenger: Wenger is one of two companies that have manufactured Swiss Army knives.  Based in Delémont, Wenger was acquired by rival Victorinox in 2005.  Since 2013, Wenger Swiss Army knives are integrated in the Victorinox collection (as the "Delémont collection"); the brand Wenger remains for watches and licensed products.

Supporting paragraphs: Wenger Swiss Army knife
Answer: World War II