Directions: Read the sentence given below and identify the two parts of the sentence that contain a grammatical/contextual error. If none of the parts of the sentence has an error, select "No error" as your answer. 

The relationship between inequality and carbon emissions (A) is complex, but addressing both environmental and socio-economical (B) inequalities is crucial for sustainable development, (C) especially in highly unequally societies like India. (D)