Explanation:
In the sentence "The store is open from 6 am till 7 pm.", the underlined word is "till."
The correct part of speech for "till" is:
(B) Adverb
Explanation:
- Till is an adverb in this case, indicating the time limit (7 pm) in the sentence.
- It functions to modify the time duration and describes until what point the store remains open.