Answer: hello options related to your question is missing attached below is the missing option
answer :
4/9 ≤ r < 1/2 ----- ( c ) 
Explanation:
Given that G denotes the centroid of triangle ABC and points M, N are points found in the interiors of segments AB,AC 
also Given that r denotes ratio of triangles AMN to triangle ABC 
attached below is a detailed solution