指出下面不符合命名规范的标识符()。 A: sUmNumber B: SumNumber C: Sum_OfNumber D: SumC)fNumber

针对如下三个实现矩阵求和的不同函数：int a[N][N];int sumA( int a[N][N] ){ int i, j; int sum = 0; for ( i = 0; i < N; i++ ) for ( j = 0; j < N; j++ ) sum += a[i][j]; return sum;}int sumB( int a[N][N] ){ int i, j; int sum = 0; for ( j = 0; j < N; j++ ) for ( i = 0; i < N; i++ ) sum += a[i][j]; return sum;}int sumC( int a[N][N] ){ int i, j; int sum = 0; for ( j = 0; j < N; j+=2 ) for ( i = 0; i < N; i+=2 ) sum += ( a[i][j] + a[i+1][j] + a[i][j+1] + a[i+1][j+1] ); return sum;}当N足够大的时候，三个函数的运行时间t1、t2、t3符合下列哪种情况？（）[/i][/i][/i][/i] A: t1 > t2 > t3 B: t3 > t1 > t2 C: t2 > t3 > t1 D: t3 > t2 > t1