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

Select the correct answer. read this excerpt from incidents in the life of a slave girl by harriet ann jacobs: among the ladies who were acquainted with my grandmother, was one who had known her from childhood, and always been very friendly to her. she had also known my mother and her children, and felt interested for them. at this crisis of affairs she called to see my grandmother, as she not unfrequently did. she observed the sad and troubled expression of her face, and asked if she knew where linda was, and whether she was safe. my grandmother shook her head, without answering. "come, aunt martha," said the kind lady, "tell me all about it. perhaps i can do something to you." which of these important concepts uncommon to abolitionist literature does jacobs depict in the excerpt? 1. some kind white characters were included in slave narratives so that northerners would not be offended. 2. southern society was complex and diverse with both good and bad people unlike northern stereotypes showed. 3. many kind slave owners and their slaves developed deep friendships. 4. most whites and blacks lived in harmony in the south and made efforts to each other. a. 1 and 4 b. 1 and 3 c. 1 and 2 d. 2 and 3