Select the option which is the most appropriate one word substitution for the given group of words.

A protected place for birds and animals

sanctuary

The most appropriate one-word substitution for the given group of words "a protected place for birds and animals" is sanctuary.

• Bunker is a heavily fortified shelter.
• Sanctuary is a place of safety or protection.
• Island is a piece of land surrounded by water.
• Estuary is the tidal mouth of a river.

The word sanctuary is the most appropriate because it specifically refers to a place where animals are protected from harm. The other words do not have the same connotation of being a place where animals are safe.