To solve this problem, we need to understand the criterion for DNA fragments movement on agarose gel during gel electrophoresis.$\newline$Gel electrophoresis is a technique used to separate DNA fragments based on their size.$\newline$Let's analyze the options:$\newline \bullet$Option 1: The smaller the fragment size, the farther it moves.$\newline$ - This is correct because smaller DNA fragments move more easily through the pores of the agarose gel, allowing them to travel farther than larger fragments.$\newline \bullet$Option 2: Positively charged fragments move to farther end.$\newline$ - This is incorrect because DNA fragments are negatively charged due to their phosphate backbone and move towards the positive electrode.$\newline \bullet$Option 3: Negatively charged fragments do not move.$\newline$ - This is incorrect because negatively charged DNA fragments do move towards the positive electrode.$\newline \bullet$Option 4: The larger the fragment size, the farther it moves.$\newline$ - This is incorrect because larger fragments encounter more resistance and move less distance compared to smaller fragments.$\newline$Therefore, the correct criterion is:$\newline$Option 1: The smaller the fragment size, the farther it moves.$\newline$This corresponds to the correct option, which is Option 1.