Starch potato begins to . . . . . . . . at a lower temperature than corn starch.

Answer: Option C

Starches from different sources have varying properties, including their gelatinization temperatures. Gelatinization refers to the process where starch granules absorb water and swell, leading to thickening of the mixture. Potato starch generally gelatinizes at a lower temperature compared to corn starch.

Let's analyze each option:

Option A: "burn" - This is not related to the gelatinization process of starches.

Option B: "smell" - This is not related to the gelatinization process of starches.

Option C: "gelatinize" - This is correct. Gelatinization is the correct term for the process where starch granules absorb water and swell.

Option D: "separate" - This is not related to the gelatinization process of starches.

Therefore, the correct answer is Option C: gelatinize.