Two chemical species X and Y combine

Two chemical species $X$ and $Y$ combine together to form a product $P$ which contains both $X$ and $Y$

$X+Y \rightarrow P$

$X$ and $Y$ cannot be broken down into simpler substances by simple chemical reactions. Which of the following concerning the species $X, Y$ 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).