The greatest value in the domain for this situation would be the maximum number of containers that the railroad car can carry while still staying within its maximum cargo weight limit of 110,000 pounds. To find this value, we can divide the maximum cargo weight by the weight of each canister:
110,000 pounds ÷ 2,000 pounds = 55 canisters
Therefore, the greatest value in the domain for this situation is 55 canisters.