Which modification enables the code fragment to compile?

Given:
IntStream stream = IntStream.of (1,2,3);
IntFunction<Integer> inFu= x -> y -> x*y; //line n1
IntStream newStream = stream.map(inFu.apply(10)); //line n2
newStream.forEach(System.output::print);
Which modification enables the code fragment to compile?

A.
Replace line n1 with:
IntFunction<UnaryOperator> inFu = x -> y -> x*y;

B.
Replace line n1 with:
IntFunction<IntUnaryOperator> inFu = x -> y -> x*y;

C.
Replace line n1 with:
BiFunction<IntUnaryOperator> inFu = x -> y -> x*y;

D.
Replace line n2 with:
IntStream newStream = stream.map(inFu.applyAsInt (10));