Final answer:
The speaker in 'Holy Thursday (Songs of Innocence)' by William Blake is an adult observer who describes a scene of orphans on Holy Thursday with awe and social critique.
Step-by-step explanation:
The speaker in the poem Holy Thursday (Songs of Innocence) by William Blake is (B) An adult observer. This poem is a part of Blake's larger work, Songs of Innocence and of Experience, which contrasts the innocent and pastoral world of childhood against an adult world of corruption and repression.
The poems reflect on the author's views of the society in which he lived, often critiquing it. Holy Thursday depicts the Holy Thursday service where orphans and other poor children of London would be paraded into St. Paul's Cathedral. The speaker, an adult observer, describes the scene with a sense of awe and critical undertones regarding the social conditions of the time.