Can someone me with this sentence?

i have to identify the italicized clause.

*where we shall go* is a secret.

is it:
adjective clause
adverb clause
noun clause
gerund phrase

In the poem, anne bradstreet discusses the themes of death and solace, or relief from pain. analyze the development of these themes in the poem. how and why does the speaker relate these two concepts? cite evidence from the poem to support your answer