Let the measures of the 2 complementary angles be α and β.
α+β are complementary means, their sum is 90°. So the measure of the remaining 3rd angle is 180°-90°=90°.
This means the triangle is a right triangle, with the length of the hypotenuse equal to 10 cm.
let the length of the sides be a and b.
So lisa can draw any right triangle, with sides a and b, such that

which means, infinitely many triangles.
Answer:
A.
More than one triangle exists with the given conditions, and all instances must be right triangles.