Two chemical substances X and Y combine together to form a product P which contains X and Y

X + Y → P

X and Y cannot be broken down into simpler substance by simple chemical reactions. Which of the following statements concerning X, Y and P are correct?

(i) P is a compound

(ii) X and Y are compounds

(iii) X and Y are elements

(iv) P has a fixed composition

(a) (i), (ii) and (iii)

(b) (i), (ii) and (iv)

(c) (ii), (iii) and (iv)

(d) (i), (iii) and (iv)