Which one of the following does not signify a battle tank?

The T-55, T-72, and T-90 are all well-documented series of main battle tanks (MBTs). The T-54/T-55 series is one of the most widely used tank families globally, originating from the Soviet Union [2]. The T-72 is a prominent Soviet-era MBT that served as the basis for the T-90, which was initially designated as the T-72BU before being renamed [1]. In contrast, the T-155 (specifically the T-155 Fırtına) is not a battle tank but a Turkish self-propelled howitzer based on the South Korean K9 Thunder chassis. While battle tanks are designed for direct fire and front-line combat, self-propelled howitzers like the T-155 are artillery pieces intended for indirect fire support. Therefore, T-155 does not signify a battle tank in the context of military armored vehicles.

Sources

1. [2] https://en.wikipedia.org/wiki/T-54/T-55_operators_and_variants
2. [1] https://en.wikipedia.org/wiki/T-90