Question: What war was the basis for the Milton Bradley Board game that modeled it's tanks after a tank sometimes referred to as the "Mark V"?

Context articles: Gamemaster (board game series)
Thunder Road (board game)
Torpedo Run!
Battle Masters
Tank Battle
Panther tank
Mark V tank
Flip-O-Potamus
The Game of Life (game show)
Fireball Island

The Gamemaster Series of board games consists of five war simulation games released by the game company Milton Bradley beginning in 1984.
 The games were not developed "in-house" by Milton Bradley, with each game initially published in limited runs by smaller game publishers in the early 1980s before their rights were acquired by Milton Bradley.
 Despite this, some modern reissues of these games refer to the Milton Bradley versions as the "first edition" of each game.
Thunder Road ("a.k.a. ThunderRoad, Le Survivant") is a post-apocalyptic themed racing board game invented by Jim Keifer and published by Milton Bradley.
 Using an assortment of four different vehicles each ranging from a modified dune buggy to a gyrocopter, players must race down an infinite roadway against one another.
 The goal of the game for players is to either be the last player team alive ("e.g., eliminate all other player vehicle teams") or simply out race ("i.e., out distance") the other teams.
 Although the game was originally published by Milton Bradley in 1986, Hasbro currently owns the rights to the game, since it acquired Milton Bradley in 1984.
Torpedo Run!
 is a 1986 board game published by Milton Bradley in which the object is to destroy your opponents ships before they can destroy yours.
 The game was part of Milton Bradley's Floor Wars Series.
 The game was well known for its large board size and large playing pieces.
Battle Masters is a board game by Milton Bradley made in collaboration with Games Workshop in 1992.
 It is a game that simulates the type of battles as seen in "Warhammer Fantasy Battle", but with much simpler game mechanics not based on its parent game.
 The game, like its sibling Milton Bradley/Games Workshop partnerships "HeroQuest" and "Space Crusade", was designed by Stephen Baker, who later went on to design the popular game "Heroscape".
Tank Battle is a Milton Bradley board game of strategy where players attempt to out-guess and out-maneuver their opponent in a contest of armored warfare, and includes the extra strategy brought by fuel and ammunition dumps as well as anti-tank guns and mines.
 The playing pieces are modeled after actual World War II tanks of the Americans and Germans, these being the M4A3 Sherman Medium Tank and the Panzerkampfwagen V Panther Ausf.
 G.
The Panther was a German medium tank deployed during World War II on the Eastern and Western Fronts in Europe from mid-1943 to its end in 1945.
 It had the ordnance inventory designation of Sd.Kfz.
 171.
 Until 27 February 1944, it was designated as the Panzerkampfwagen" V "Panther when Hitler ordered that the Roman numeral "V" be deleted.
 Contemporary English language reports sometimes refer to it as the "Mark V".
The British Mark V tank was an upgraded version of the Mark IV tank.
 It was first deployed in 1918, used in action during the closing months of World War I, and in the Allied intervention in the Russian Civil War on the White Russian side, and by the Red Army, after they were captured.
 The tank was improved in several aspects, chiefly the new steering system and engine, but it fell short in other areas such as mechanical reliability and its insufficient ventilation.
 However, the Mark V was successful, especially given its limited service history, and primitive design.
Flip-O-Potamus is a Milton Bradley board game released in 1986.
 Flip-O-Potamus is part of the T.H.I.N.G.S. family of games (Totally Hilarious Incredible Neat Games of Skill).
The Game of Life was an American television series on The Hub (now Discovery Family).
 The program, hosted by Frank Nicotero, is based on the Milton Bradley board game The Game of Life.
 It premiered on September 3, 2011 with a special "preview" episode, and began its official run two weeks later on September 17, 2011, airing on Saturday nights.
 The series ended on April 22, 2012 and last aired on December 31, 2013.
Fireball Island is a board game first published by Milton Bradley in 1986.
 The tagline is ""The dimensional adventure game of pitfalls and perils!""
 It is set on an unexplored tropical island, the home of the primitive idol Vul-Kar.
 Players progress along winding paths around the island, avoiding fireballs and trying to capture Vul-Kar's jewel and carry it to the escape boat.
 Game concept originally developed by artist / toy designers Bruce Lund and Chuck Kennedy.
 The game was licensed to Milton Bradley by Anjar Co., an international toy licensing company and co-licensor of the game.