Four solutions were tested to see whether they contained protein, starch or glucose.
The colours of the solutions after the tests are recorded in the table.
Which solution contained protein and glucose but not starch?

The biuret test is a chemical test that can be used to check for the presence of peptide bonds in a given analyte. A positive test is indicated by a purple color due to the copper ion complex with the amide group of the protein. Hence solution C and D have proteins.
Now in the next step iodine test is conducted, Amylose in starch is responsible for the formation of a deep blue color in the presence of iodine. As shown in the table, solution B and D turned blue-black, therefore we can conclude that solution A and C does not have starch.
Benedict's test is a chemical test that can be used to check for the presence of reducing sugars (such as glucose) in a given analyte. Therefore, when reducing sugars are present in the analyte, the cupric ions ($C{u}^{2+}$) in Benedict's reagent are reduced to cuprous ions ($C{u}^{+}$). These cuprous ions form copper(I) oxide with the reaction mixture and precipitate out as a brick-red/orange coloured compound.
Hence, it is quite evident that amongst the four solutions, solution C has proteins as well as glucose but it lacks starch.