Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Name/ designation | Year of intro | Country of origin | Primary cartridge | Type |
| --- | --- | --- | --- | --- |
| M1 Bazooka | 1942.0 | United States | 60mm | Recoilless |
| M2GC | 1948.0 | Sweden | 84mm | Recoilless |
| Northover Projector | 1940.0 | United Kingdom | 63.5mm | Recoilless |
| Panzerfaust | 1943.0 | Germany | 150mm | Recoilless |
| PIAT | 1942.0 | United Kingdom | 86mm | Spigot mortar |
| Rifleman's Assault Weapon | 1977.0 | United States | 140mm | Close support rocket |
| RPG-2 | 1949.0 | Soviet Union | 40mm | Reusable |
| RPG-7 | 1961.0 | Soviet Union | 40mm | Reusable |
| RPG-16 | 1970.0 | Soviet Union | 58.3mm | Reusable |
| RPG-18 | 1972.0 | Soviet Union | 64mm | Disposable |
| RPG-22 | 1985.0 | Soviet Union | 72.5mm | Disposable |
| RPG-26 | 1985.0 | Soviet Union | 72.5mm | Disposable |
| RPG-27 | 1989.0 | Soviet Union | 105mm | Disposable |
| RPG-28 | 2007.0 | Russia | 125mm | Disposable |
| RPG-29 | 1989.0 | Soviet Union | 40mm | Reusable |
| RPG-30 | 2008.0 | Russia | 105mm | Disposable |
| RPG-32 | 1961.0 | Russia | 40mm | Reusable |
| RPG-76 | 1985.0 | Poland | 68mm | Disposable |
| Type 69 RPG | 1969.0 | China | 40mm | Reusable |
| Yasin | 2004.0 | Palestine | 40mm | Reusable |
Question:
What is Country of Origin, when Year of Intro is 1977?
Answer:
United States