Which combination of the following features will suffice to characterize an $$OS$$ as a multi-programmed $$OS?$$
$$(a).$$ More than one program may be loaded into main memory at the same time for execution.
$$(b).$$ If a program waits for certain events such as $$I/O$$, another program is immediately scheduled for execution.
$$(c).$$ If the execution of a program terminates, another program is immediately scheduled for execution.

Consider the following declaration of a two-dimensional array in C:

char a[100][100];

Assuming that the main memory is byte-addressable and that the array is stored starting from memory address 0, the address of a[40][50] is

The results returned by function under value-result and reference parameter passing conventions

In the C language