Could somebody help me on this one. Due in 3 min

Plz me plz i need and plz delte this after answer

Which representation has a constant of variation of -2.5

Which of these side lengths could form a triangle a) 2 cm , 2 cm , 4 cm b) 3 cm , 5 cm , 10 cm c) 3 cm , 4 cm , 5 cm d) 4 cm , 8 cm , 15 cm