In a library database, there are entities for "Book" $($E$1)$ and "Author" $($E$3).$ What is the likely relationship type between Book and Author?

a$.$

N$-$M $($Many$-$to$-$Many$)$

b$.$

N$-1($Many$-$to$-$One$)$

c$.$

$1-$N $($One$-$to$-$Many$)$

d$.$

$1-1($One$-$to$-$One$)$