Seeking property-casualty insurance is the most appropriate measure for Mr. Brad to protect his building and avoid losses resulting from large-scale compensations. Property insurance would provide protection against damage to the building resulting from fire, theft, water damage, etc. Casualty insurance, on the other hand, would provide protection against legal liability exposures, such as injuries to visitors in case of an inferno or the occurrence of any risk. This combination of property and casualty insurance would ensure that Mr. Brad is covered for both physical damages to his property and any liabilities arising from injuries or damages sustained by others. Therefore, this choice is the most comprehensive and suitable option for Mr. Brad to safeguard his interests.

Choice A is incorrect. Making life insurance and disability insurance mandatory for every tenant and visitor would not provide Mr. Brad with protection against potential losses. These types of insurances are personal coverages that protect the insured individuals, not the property owner, in case of death or disability.

Choice B is incorrect. Reinsuring the building against large-scale loss could potentially help to mitigate some financial risk associated with a major accident, but it does not directly protect Mr. Brad from liability claims arising from injuries to residents and third parties.

Choice C is incorrect. While property insurance would cover damages to the building itself due to accidents like fire, it does not typically include liability coverage for injuries or damages suffered by third parties on the premises.