Triples and quadruples are actually representations of intermediate code .
Triple is defined as :
Each instruction in triples presentation has three fields : op, arg1, and arg2.The results of respective sub-expressions are denoted by the position of expression.
So the disadvantage which is evident is we can change the position of statements and hence inefficient from a code optimization point of view.
But the advantage is less space is required as compared to quadruple notation.
Hence C) should be the correct answer.