Answer:
Friendly-looking Dog.
Step-by-step explanation:
The above pair illustrates the most correct and appropriate use of a hyphen as it is referred to as the punctuation mark that is employed to combine the meaning of two words or syllables that enhances the meaning of the words. It could be used to join two adjectives for example "rock-hard cake" or two verbs "load-bearing walls" or a noun to an adjective "dog-friendly" but while using it should be kept in mind that hyphen acts as modifier and thus, the words should function together which is best justified by "friendly-looking dog" here as it suggests the nature of dogs. The other two seem functioning less together.