4. If the following conditions about a triangle are known, the one that cannot uniquely determine the shape of the triangle is ( ).
(A) the ratio of two sides and the included angle
(B) the ratio of the three altitudes
(C) the ratio of the three medians
(D) the ratio of one side and the altitude to that side
4. D

Translate the text above into English, please retain the original text's line breaks and format, and output the translation result directly.