This is vague. Any dimensions that make a triangle can make more than one, just draw another right next to it. What's really being asked is which dimensions can make more than one non-congruent triangle.
A. Three angles measuring 75°,45°, and 60°.
That's three angles, and 75+45+60 = 180, so it's a legit triangle. The angles don't determine the sides, so we have whole family of similar triangles with these dimensions. TRUE
B. 3 sides measuring 7, 10, 12?
Three sides determine the triangles size and shape uniquely; FALSE
C. Three angles measuring 40°, 50°, and 60°?
40+50+60=150, no such triangle exists. FALSE
D. 3 sides measuring 3,4,and 5
Again, three sides uniquely determine a triangle's size and shape; FALSE