Is the phrase "honest air" an example of metaphor or personification?

The correct answer regarding the literary device used in
the phrase "honest air" is personification.

Personification
is the giving of human characteristics to non-human/non-living
things.

A metaphor is a comparison between two things not
using the words "like" or "as" in the comparison. If one uses "like" or "as" then the
comparison would be considered a simile.

Given that air is
not a human, air simply cannot be honest. Only humans can be honest. Example of
personification, so that you are able to identify the devices more easily
are:

whispering trees, screaming tides, laughing grasses,
waving trees.

Examples of metaphors would
be:

Life is a highway (comparison of life and a
highway).

She is a pig (comparison between a woman/girl and
a pig).

To change the phrase "honest air" into a metaphor,
one would do the following: the air is honest Abe.