Which submunition is specifically designed as an anti-tank mine?

The BLU-91/B is specifically designed as an anti-tank mine, intended for use against armored vehicles. It functions through a combination of mechanisms that ensure effective targeting of tanks and other armored equipment. The design of the BLU-91/B incorporates features that enable it to be dispersed in an area and initiate a detonation when a vehicle comes into its proximity, thus serving its purpose effectively in combat scenarios.

The other options represent different types of munitions with distinct functions. For example, the BLU-92/B is typically categorized as a herbicide, whereas the BLU-108/B is a smart submunition designed to target armored vehicles with a greater degree of precision, employing a terminal guidance system rather than functioning solely as a mine. The BLU-113/B is a penetrator designed for deep penetration of hardened targets, thus differentiating its application from that of an anti-tank mine. The specificity of the BLU-91/B for anti-tank purposes is what sets it apart in this context.