P
$x+y = 1$ ....$eq(i)$
$3x+3y = 3$....$eq(ii)$
$5x+5y = 5$...$eq(iii)$
As we can see
$2*eq(i) + eq(ii) = eq(iii)$ this rule is satisfied by both the LHS and RHS parts of the equations.
$\implies$ they can have infinite solution
$\implies$ They are having consistent solutions.
Q
$x+y = 3$ ....$eq(i)$
$2x+2y = 4$....$eq(ii)$
$5x+5y = 12$...$eq(iii)$
As we can see
$eq(i) + 2*eq(ii) = eq(iii)$ this rule is satisfied by the LHS part and not by the RHS parts of the equations.(i.e. $3+4*2\neq 12$)
$\implies$ They have no solution
$\implies$ They are having inconsistent solution.
$\therefore$ Option $C.$ is the correct answer