Incomplete starch digestion in short incubation Steps:

• Iodine test detects starch; original starch solution turns blue-black (positive).
• Benedict's test detects reducing sugars; starch is non-reducing, so original sample is negative.
• Amylase breaks starch into maltose (reducing sugar), but 10-minute incubation yields insufficient maltose for positive Benedict's.
• Thus, treated sample's Benedict's test remains negative.

Why C is correct:

• C (✓ x x) reflects iodine positive for starch, both Benedict's negative due to no initial sugars and incomplete hydrolysis per enzyme kinetics (rate limited by time).

Why the others are wrong:

• A: Falsely shows negative iodine and positive original Benedict's, ignoring starch properties.
• B: Erroneously assumes 10 minutes produces detectable reducing sugars.
• D: Wrongly indicates negative iodine for starch-present solution.

Final answer: C