If only half arrives then the orchestra wouldnt be correct. For a sentence fragment, if you have half of a correct sentence and the other is incorrect... it doesnt work.
1) The subject is b. Kayla
2) The subject is a. I
Explanation: A subject is the noun performing an action at the beginning of the sentence
A. main ideas and B. all ideas
Explanation:
we wont know what book your talking about unless you tell us
