Which of the following is the hashing function for separate chaining?

(a) H(x)=(hash(x)+f(i)) mod table size

(b) H(x)=hash(x)+i^2 mod table size

(c) H(x)=x mod table size

(d) H(x)=x mod (table size * 2)

This interesting question is from Hash Tables in chapter Hash Tables of Data Structures & Algorithms I

The question was posed to me in final exam.