Final answer:
William Blake's "The Lamb" from Songs of Innocence is best categorized as pastoral poetry, which idealizes rural life and nature and symbolizes innocence and purity.
Step-by-step explanation:
The type of poetry that "The Lamb" from Songs of Innocence by William Blake represents is pastoral poetry. This is option d. This genre of poetry deals with rural life and the natural world, often idealizing shepherd life and nature. It typically includes themes of innocence, peace, and simplicity. The lamb in the poem symbolizes innocence and purity, aspects commonly associated with pastoral themes. Moreover, the poem incorporates a lyrical quality through its rhythm and rhyme scheme, embodying the characteristics of lyrical poetry as well. However, the most fitting category for "The Lamb" is pastoral due to its content and symbolism that align with the pastoral tradition.