Answer:
(c) Kayla
Step-by-step explanation:
You want to identify the subject of the given sentence.
Subject
An English sentence generally consists of a subject and predicate, each of which may have various modifiers. There may be additional clauses, which also may have their own subject and predicate.
In the given sentence, its most basic form is ...
Kayla has come.
In this sentence, the subject is Kayla.