What part of the fugue comes after the subject and is stated in a new key? A. Motive
B. Theme
C. Answer
D. Fragment

is d

Explanation:

cycles in Exposition: In the first section of fugue ... Usually based on motives and fragments stated in first part of fugue. ... (can be dominant or tonic pedal in each key in a series of keys). ... Coda (codetta), the final entry, sometimes following a deceptive cadence, often over a tonic pedal.

your word would be isle.

isle is an island or peninsula especially a small one.

if you add the letter "a" you get aisle, which is a passage between 2 rows of something like chairs, shelves, or something else.