Which of the following reactions have a positive ∆ Srxn ?
(a) A(s) + B(g) ⟶ 2C(g)
(b) 2A(g) + 2B(g) ⟶ 5C(g)
(c) 2A(g) + 2B(g) ⟶ 3C(g)
(d) A(g) + 2B(g) ⟶ 2C(g)