How does the poem brilliantly indicates the goldfinch as two different aspects simile and metaphor? Labournum top poem

In the 'Laburnum Top' poem,  'sleek as lizard' is a good example of simile in the poem, likewise 'energy of her family' is an example of metaphor in the poem. Here the engine represents the mother goldfinch while the machine represents the nest with its bird chicks.

Explanation:

The poet compared the sleek movement of the Goldfinch  with that of a lizard, symbolizing the use of simile. In this poem, the Laburnum tree and goldfinch is used as a symbol of life and its changes. The visit of the goldfinch to the Laburnum tree results in fluctuations.

The visit of the goldfinch transforms the Laburnum tree and revives it, the the chicks of the the goldfinch starts to chirp on sighting her. In the poem, it conveys the message that without the goldfinch, the tree is just like another tree.

i think that it is letter d.

a is the indefinite article