(a)Since arguments are not copied into the new variables, it provides greater time and space efficiency

(b)The function can change the value of the argument and the change is reflected in the calling function

(c)A function can return only one value. In case we need to return multiple values, we can pass those arguments by reference, so that the modified values are visible in the calling function

(d)If inadvertent changes are caused to variables in called function then these changes would be reflected in calling function as original values would have been overwritten