Select the option that can be used as a one-word substitute for the given group of words.

A tank for fish or water plants

Aquarium 

The correct option is aquarium. It means "a tank in which fish or other aquatic animals are kept." The other options are not correct substitutes.

• Reservoir is a large lake or pond used to store water.
• Aviary is a large cage or area in which birds are kept.
• Museum is a building where collections of valuable and interesting objects are kept and shown to the public.