Which of the following actions could lead to being held liable for nuisance?

Playing music at a loud volume could indeed lead to being held liable for nuisance because it may interfere with the enjoyment of property by others in the vicinity. Nuisance law is primarily concerned with balancing one person's right to use their property and the impact that may have on neighboring properties or the community at large. Excessive noise, such as loud music, can be a significant disturbance, inconveniencing neighbors and disrupting their peace and enjoyment of their own properties.

In contrast, planting trees is generally a normal use of one’s property that does not typically constitute a nuisance unless it significantly obstructs light or air to a neighbor's property. Similarly, using one's own property for personal projects usually falls within the rights of property ownership, only crossing into nuisance territory if those projects significantly disrupt neighbors or violate local ordinances. Keeping a tidy yard is generally seen as responsible property maintenance and does not typically lead to nuisance claims, as it is unlikely to negatively impact the enjoyment of nearby properties.