In the following question, some part of the sentence may have errors. Find out which part of the sentence has an error and select the appropriate option. If a sentence is free from error, select 'No Error'.
The two children were(A)/identical except for(B)/the colour for their eyes.(C)/No error(D)
____________ means that the President of India can refer any matter that is of public importance or that which involves interpretation of Constitution to Supreme Court for advice.