A teacher askes four students to write three measurements that will make more than one triangle and explain why. The table shows the students' responses. Joshua 4cm, 7cm, and 15cm can make more than one triangle because 4+7=11 and 11<15.
Melanie 9ft, 14ft, and 19ft can make more than one triangle because 9+14=23 and 23>19.
Austin 50o, 50o, and 50o can make more than one triangle because the angles are equal.
Zachary 110o, 40o, 30o can make more than one triangle because the angles add up to 180o.
Which student is correct?

a Joshua

b Melanie

c Austin

d Zachary