Abigail is the owner of a tract of land, but Umberto owns the mineral and excavation rights to that land. Umberto commences excavation in order to access the valuable minerals. While digging, he causes the surface of the land to collapse. Umberto is
a. not liable for any damage
b. absolutely liable for any collapse
c. liable only if Umberto acted recklessly
d. liable only if Umberto acted negligently

Umberto will be liable only if he acted negligently and performed a bad excavation or did not take the proper measures to avoid the land to collapse. This is represented in option "d" and that will be the correct answer.

Explanation:

The remaining options a, b,c can be used if we know the land conditions and Umberto expertise doing excavations. The only thing we know is that the surface of the land collapse during the excavations.