Let $S$ denote the sum of the first $n$ terms of an arithmetic sequence $\left\{ a _ { n } \right\}$. If $a _ { 4 } + a _ { 5 } = 24$ and $S _ { 6 } = 48$, then the common difference of $\left\{ a _ { n } \right\}$ is A. 1 B. 2 C. 4 D. 8
Let $S$ denote the sum of the first $n$ terms of an arithmetic sequence $\left\{ a _ { n } \right\}$. If $a _ { 4 } + a _ { 5 } = 24$ and $S _ { 6 } = 48$, then the common difference of $\left\{ a _ { n } \right\}$ is
A. 1
B. 2
C. 4
D. 8