Two conductors have the same resistance at $0^{\circ}C$ but their temperature coefficients of resistance are $\alpha_1$ and $\alpha_2$. The respective temperature coefficients of their series and parallel combinations are nearly

Question

( A ) $\frac{\alpha_1 + \alpha_2}{2}, \alpha_1 + \alpha_2$
( B ) $\frac{\alpha_1 + \alpha_2}{2}, \frac{\alpha_1 + \alpha_2}{2}$
( C ) $\alpha_1 + \alpha_2, \frac{\alpha_1 + \alpha_2}{2}$
( D ) $\alpha_1 + \alpha_2, \frac{\alpha_1 \alpha_2}{\alpha_1 + \alpha_2}$