4. Given that $a, b, c$ are distinct real numbers, and
$$
\begin{array}{l}
L=\frac{1}{(a-b)(a-c)}, M=\frac{1}{(b-a)(b-c)}, \\
N=\frac{1}{(c-a)(c-b)} .
\end{array}
$$

Then among the following conclusions:
(1) $a L+b M+c N=0$,
(2) $a^{2} L+b^{2} M+c^{2} N=1$,
(3) $a^{3} L+b^{3} M+c^{3} N=a+b+c$, the number of correct conclusions is ( ).
(A) 0
(B) 1
(C) 2
(D) 3